2024-03-28T13:08:16Z
http://eprints.adm.unipi.it/cgi/oai2
oai:eprints.adm.unipi.it:1
2010-12-20T10:44:57Z
oai:eprints.adm.unipi.it:75
2010-12-20T10:43:24Z
oai:eprints.adm.unipi.it:493
2010-12-20T10:56:29Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/493/
Adiabatic divergence of the chaotic layer width and acceleration of chaotic and noise-induced transport
Soskin, Stanislav Maratovich
Mannella, Riccardo
Yevtushenko, Oleg M.
FIS/03 - Fisica della materia
SUMMARY We show that, in spatially periodic Hamiltonian systems driven by a time-periodic coordinate-independent (AC) force, the upper energy of the chaotic layer grows unlimitedly as the frequency of the force goes to zero. This remarkable effect is absent in any other physically significant systems. It gives rise to the divergence of the rate of the spatial chaotic transport. We also generalize this phenomenon for the presence of a weak noise and weak dissipation. We demonstrate for the latter case that the adiabatic AC force may greatly accelerate the spatial diffusion and the reset rate at a given threshold.
2008
Article
PeerReviewed
application/pdf
it
http://eprints.adm.unipi.it/493/1/marseille-journal_revised.pdf
Soskin, Stanislav Maratovich and Mannella, Riccardo and Yevtushenko, Oleg M. (2008) Adiabatic divergence of the chaotic layer width and acceleration of chaotic and noise-induced transport. Communications in Nonlinear Science and Numerical Simulation, 14/200 . ISSN 1007-5704 (In Press)
http://www.sciencedirect.com/science/article/B6X3D-4SXYFYP-2/1/283456246909c2f7a6c0a7ca2d4275ef
doi:10.1016/j.cnsns.2008.06.025
oai:eprints.adm.unipi.it:602
2010-12-20T10:51:02Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/602/
Sub-Doppler spectroscopy of atoms excited in the regime of Rabi oscillations in a thin gas cell
Beverini, Nicolò
Izmailov, Azad
FIS/03 - Fisica della materia
We carried out theoretical investigation about velocity-selective atomic excitation on long–lived (metastable) levels of an atomic vapour in a thin cell by a monochromatic laser beam, running in the normal direction. The regime of coherent Rabi oscillations is considered on the light-induced transition from a sublevel of the ground quantum term to a metastable atomic level. On the basis of density matrix equations for the two-level system, we analysed the atomic population density of the metastable level, when the sample is irradiated by resonant monochromatic laser beam with an annular cross-section versus atomic velocities and versus the detuning, the amplitude, and the geometry of the laser beam. It is shown that, in the centre of the annular region, it can be obtained a population distribution on the metastable level as a function of the laser detuning, characterized by a sharp narrow resonance profile, whose width is reduced with respect to the thermal Doppler width roughly by the ratio between the diameter of the irradiated region and the inner thickness of the cell. We suggest high-sensitive schemes, in order to detect these sub-Doppler resonances, by probing the population of the metastable state with a second laser beam, resonant with a transition leaving from the metastable level. The case of 1S0?3P1 spin-forbidden transition of Ca is discussed in more detail.
2009
Article
PeerReviewed
application/pdf
it
http://eprints.adm.unipi.it/602/1/Opt_Commun_09.pdf
Beverini, Nicolò and Izmailov, Azad (2009) Sub-Doppler spectroscopy of atoms excited in the regime of Rabi oscillations in a thin gas cell. Optics Communications, 282 . pp. 2527-2531. ISSN 0030-4018
http://www.sciencedirect.com/science?_ob=MImg&_imagekey=B6TVF-4VXC018-3-F&_cdi=5533&_user=793840&_orig=browse&_coverDate=07%2F01%2F2009&_sk=997179986&view=c&wchp=dGLbVzz-zSkWz&md5=49789d5fc8a003a06c73976bc5cf0807&ie=/sdarticle.pdf
doi:10.1016/j.optcom.2009.03.018
oai:eprints.adm.unipi.it:613
2010-12-20T10:50:31Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
7375626A656374733D417265613032:4649532F3037
74797065733D61727469636C65
http://eprints.adm.unipi.it/613/
Relation between configurational entropy and relaxation dynamics of glass-forming systems under volume and temperature reduction
Capaccioli, Simone
Prevosto, Daniele
Lucchesi, Mauro
Amirkhani, Masoud
Rolla, Pierangelo
FIS/03 - Fisica della materia
FIS/07 - Fisica applicata (a beni culturali, ambientali, biologia e medicina)
SUMMARY The structural relaxation dynamics of two molecular glass-forming systems have been analyzed by means of dielectric spectroscopy, under cooling and compression conditions. The relation of the dynamic slowing down with the reduction of the configurational entropy, SC, as predicted by Adam and Gibbs (AG), was also investigated. As SC is not directly accessible by experiments, it was estimated, following a common procedure in literature, from the excess entropy Sexc of the supercooled liquid with respect to the crystal, determined from calorimetric and expansivity measurements over the same T–P range of dynamics investigation. The AG relation, predicting linear dependence between the logarithmic of structural relaxation time and the reciprocal of the product of temperature with configurational entropy, was successfully tested. Actually, a bilinear relation between Sexc and SC was found, with different proportionality factors in isothermal and isobaric conditions. Using such results, we derived an equation for predicting the pressure dependence of the glass transition temperature, in good accordance with the experimental values in literature.
2009
Article
PeerReviewed
application/pdf
it
http://eprints.adm.unipi.it/613/1/JNCS2009entropy.pdf
Capaccioli, Simone and Prevosto, Daniele and Lucchesi, Mauro and Amirkhani, Masoud and Rolla, Pierangelo (2009) Relation between configurational entropy and relaxation dynamics of glass-forming systems under volume and temperature reduction. Journal of Non-Crystalline Solids, 355 (10-12). pp. 753-758. ISSN 0022-3093
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TXM-4W1R9SV-K&_user=793840&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_acct=C000043460&_version=1&_urlVersion=0&_userid=793840&md5=17491dda970b7555605caa26cdaeb078
doi: 10.1016/j.jnoncrysol.2009.01.034
oai:eprints.adm.unipi.it:713
2010-12-21T12:42:51Z
7374617475733D707562
7375626A656374733D417265613031:4D41542F3037
7375626A656374733D417265613032:4649532F3035
74797065733D61727469636C65
http://eprints.adm.unipi.it/713/
Canonical elements for Opik theory
Tommei, Giacomo
MAT/07 - Fisica matematica
FIS/05 - Astronomia e astrofisica
SUMMARY The purpose of this paper is to find a set of canonical elements to use within the framework of O¨ pik theory of close encounters of a small body with a planet (O¨ pik, Interplanetary Encounters, 1976). Since the small body travels along a planetocentric hyperbola during the close approach and O¨ pik formulas are valid, without approximations, only at collision, we derive a set of canonical elements for hyperbolic collision orbits (eccentricity e→1+, semi-major axis a fixed) and then we introduce the unperturbed velocity of the small body and the distance covered along the asymptote as a new canonically conjugate pair of orbital elements. An interesting result would be to get a canonical set containing the coordinates in the Target Plane (TP), useful for the analysis of the future encounters: in the last part we prove that this is not possible.
2006
Article
PeerReviewed
application/pdf
en
http://eprints.adm.unipi.it/713/1/opikcan_eprint.pdf
Tommei, Giacomo (2006) Canonical elements for Opik theory. Celestial Mechanics and Dynamical Astronomy, 94 (2). pp. 173-195. ISSN 1572-9478
http://springerlink.com/content/07666702j58710m5/?p=97bbcec253f8433194eb580ee4b2dd87&pi=2
DOI 10.1007/s10569-005-4820-3
oai:eprints.adm.unipi.it:714
2010-12-21T12:43:34Z
7374617475733D707562
7375626A656374733D417265613039:494E472D494E442F3033
7375626A656374733D417265613031:4D41542F3037
7375626A656374733D417265613032:4649532F3035
74797065733D61727469636C65
http://eprints.adm.unipi.it/714/
Orbit determination of space debris: admissible regions
Tommei, Giacomo
Milani, Andrea
Rossi, Alessandro
ING-IND/03 - Meccanica del volo
MAT/07 - Fisica matematica
FIS/05 - Astronomia e astrofisica
SUMMARY The main problem in the orbit determination of the space debris population orbiting our planet is identifying which separate sets of data belong to the same physical object. The observations of a given object during a passage above an observing station are collectively called a Too Short Arc (TSA): data from a TSA cannot allow for a complete determination of an orbit. Therefore, we have to solve first the identification problem, finding two or more TSAs belonging to the same physical object and an orbit fitting all the observations. This problem is well known for the determination of orbits of asteroids: we shall show how to apply the methods developed for preliminary orbit determination of heliocentric objects to geocentric objects. We shall focus on the definition of an admissible region for space debris, both in the case of optical observations and radar observations; then we shall outline a strategy to perform a full orbit determination.
2007
Article
PeerReviewed
application/pdf
en
http://eprints.adm.unipi.it/714/1/deb_admreg_eprint.pdf
Tommei, Giacomo and Milani, Andrea and Rossi, Alessandro (2007) Orbit determination of space debris: admissible regions. Celestial Mechanics and Dynamical Astronomy, 97 (4). pp. 289-304. ISSN 1572-9478
http://springerlink.com/content/45880w867p5jq862/?p=3437e876557f401bb23e30ea4d4c7d50&pi=3
doi 10.1007/s10569-007-9065-x
oai:eprints.adm.unipi.it:721
2010-12-20T10:46:16Z
7374617475733D707562
7375626A656374733D417265613031:4D41542F3037
7375626A656374733D417265613032:4649532F3035
74797065733D61727469636C65
http://eprints.adm.unipi.it/721/
Nonlinear impact monitoring: line of variation searches for impactors
Milani, Andrea
Chesley, Steven R.
Sansaturio, Maria Eugenia
Tommei, Giacomo
Valsecchi, Giovanni Battista
MAT/07 - Fisica matematica
FIS/05 - Astronomia e astrofisica
SUMMARY When a new near Earth asteroid is discovered, it is important to know whether or not there is the possibility of an impact with the Earth in the near future. In this paper, we describe the technical approaches employed by the two operational second-generation asteroid impact monitoring systems, CLOMON2 and Sentry, paying particular attention to the similarities and differences between these independent systems. The detection and characterization of a potential impact requires the propagation of the orbital probability density function from the time of discovery to the time of hypothetical impact. Since the N-body problem is not integrable, this can be done only by sampling the orbital elements space with a finite number of Virtual Asteroids (VAs), the orbit of each one being propagated numerically. Our methods, illustrated in this paper, use the Line Of Variation (LOV), a unidimensional subspace, to perform this sampling. The primary goal is to detect Virtual Impactors (VIs), which are regions in the initial conditions space leading to dynamically distinct collision solutions; then a probability integral needs to be computed on the volume of the VI. An important issue is how to assure completeness of such a search down to some impact probability threshold. This problem cannot be efficiently solved just by computing more VAs, but requires a geometric description of the behavior of the LOV in order to identify the critical segments of this curve. We have studied these behaviors on the Target Plane (TP) through our analytical theory and the output of many numerical tests. Assuming that the geometry is the simplest compatible with the data available from the sampling, we obtain a classification which allows us to use iterative methods, appropriate for each case, to find the closest approach distance possible along the LOV. After an LOV minimum has been identified, it is possible to use a probability density linearized at this point. However, when the cross section of the Earth is not crossed by the LOV, there is no guarantee that nonlinearity would be negligible in the direction on the TP transversal to the LOV. We describe how to test for such nonlinearity, and thus reduce or eliminate the possibility of spurious VIs. In this way, the performance of our impact monitoring systems has been significantly increased in comparison to the earlier and simpler solitary system. These more advanced systems have identified and then eliminated (through additional observations) more than one hundred cases of asteroids with VIs in the years 2002–2003.
2005-02
Article
PeerReviewed
application/pdf
en
http://eprints.adm.unipi.it/721/1/clomon2_eprint.pdf
Milani, Andrea and Chesley, Steven R. and Sansaturio, Maria Eugenia and Tommei, Giacomo and Valsecchi, Giovanni Battista (2005) Nonlinear impact monitoring: line of variation searches for impactors. Icarus, 173 (2). pp. 362-384. ISSN 0019-1035
http://www.sciencedirect.com/science/journal/00191035
doi:10.1016/j.icarus.2004.09.002
oai:eprints.adm.unipi.it:722
2010-12-20T10:46:26Z
7374617475733D707562
7375626A656374733D417265613031:4D41542F3037
7375626A656374733D417265613032:4649532F3035
74797065733D61727469636C65
http://eprints.adm.unipi.it/722/
Multiple solutions for asteroid orbits: Computational procedure and applications
Milani, Andrea
Sansaturio, Maria Eugenia
Tommei, Giacomo
Arratia, Oscar
Chesley, Steven R.
MAT/07 - Fisica matematica
FIS/05 - Astronomia e astrofisica
We describe the Multiple Solutions Method, a one-dimensional sampling of the six-dimensional orbital confidence region that is widely applicable in the field of asteroid orbit determination. In many situations there is one predominant direction of uncertainty in an orbit determination or orbital prediction, i.e., a ``weak'' direction. The idea is to record Multiple Solutions by following this, typically curved, weak direction, or Line Of Variations (LOV). In this paper we describe the method and give new insights into the mathematics behind this tool. We pay particular attention to the problem of how to ensure that the coordinate systems are properly scaled so that the weak direction really reflects the intrinsic direction of greatest uncertainty. We also describe how the multiple solutions can be used even in the absence of a nominal orbit solution, which substantially broadens the realm of applications. There are numerous applications for multiple solutions; we discuss a few problems in asteroid orbit determination and prediction where we have had good success with the method. In particular, we show that multiple solutions can be used effectively for potential impact monitoring, preliminary orbit determination, asteroid identification, and for the recovery of lost asteroids.
2005
Article
PeerReviewed
application/pdf
en
http://eprints.adm.unipi.it/722/1/multsol_eprint.pdf
Milani, Andrea and Sansaturio, Maria Eugenia and Tommei, Giacomo and Arratia, Oscar and Chesley, Steven R. (2005) Multiple solutions for asteroid orbits: Computational procedure and applications. Astronomy & Astrophysics, 431 . pp. 729-746.
http://www.aanda.org/index.php?option=article&access=bibcode&bibcode=2005A%2526A...431..729MFUL
10.1051/0004-6361:20041737
oai:eprints.adm.unipi.it:1284
2013-07-30T11:09:46Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1284/
On the time dependence of the $h$-index
Mannella, Riccardo
Rossi, Paolo
FIS/03 - Fisica della materia
SUMMARY The time dependence of the $h$-index is analyzed by considering the average
behaviour of $h$ as a function of the academic age $A_A$ for about 1400 Italian
physicists, with career lengths spanning from 3 to 46 years. The individual
$h$-index is strongly correlated with the square root of the total citations
$N_C$: $h \approx 0.53 \sqrt{N_C}$. For academic ages ranging from 12 to 24
years, the distribution of the time scaled index $h/\sqrt{A_A}$ is
approximately time-independent and it is well described by the Gompertz
function. The time scaled index $h/\sqrt{A_A}$ has an average approximately
equal to 3.8 and a standard deviation approximately equal to 1.6. Finally, the
time scaled index $h/\sqrt{A_A}$ appears to be strongly correlated with the
contemporary $h$-index $h_c$.
2012-07-15
Article
NonPeerReviewed
Mannella, Riccardo and Rossi, Paolo (2012) On the time dependence of the $h$-index. arXiv . (In Press)
http://arxiv.org/abs/1207.3499v1
oai:eprints.adm.unipi.it:1285
2013-07-30T11:01:26Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1285/
Landau-Zener transitions in the presence of harmonic noise
Kraft, Matthias
Burkhardt, Stephan
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY We study the influence of off-diagonal harmonic noise on transitions in a
Landau-Zener model. We demonstrate that the harmonic noise can change the
transition probabilities substantially and that its impact depends strongly on
the characteristic frequency of the noise. In the underdamped regime of the
noise process, its effect is compared with the one of a deterministic
sinusoidally oscillating function. While altering the properties of the noise
process allows one to engineer the transitions probabilities, driving the
system with a deterministic sinusoidal function can result in larger and more
controlled changes of the transition probability. This may be relevant for
realistic implementations of our model with Bose-Einstein condensates in
noise-driven optical lattices.
2013-03-08
Article
NonPeerReviewed
Kraft, Matthias and Burkhardt, Stephan and Mannella, Riccardo and Wimberger, Sandro (2013) Landau-Zener transitions in the presence of harmonic noise. arXiv . (In Press)
http://arxiv.org/abs/1303.1864v1
oai:eprints.adm.unipi.it:1286
2013-07-30T11:00:10Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1286/
Noise assisted transport in the Wannier-Stark system
Burkhardt, Stephan
Kraft, Matthias
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY We investigated how the presence of an additional lattice potential, driven
by a harmonic noise process, changes the transition rate from the ground band
to the first excited band in a Wannier-Stark system. Alongside numerical
simulations, we present two models that capture the essential features of the
dynamics. The first model uses a noise-driven Landau-Zener approximation and
describes the short time evolution of the full system very well. The second
model assumes that the noise process' correlation time is much larger than the
internal timescale of the system, yet it allows for good estimates of the
observed transition rates and gives a simple interpretation of the dynamics.
One of the central results is that we obtain a way to control the interband
transitions with the help of the second lattice. This could readily be realized
in state-of-the-art experiments using either Bose-Einstein condensates or
optical pulses in engineered potentials.
2013-02-06
Article
NonPeerReviewed
Burkhardt, Stephan and Kraft, Matthias and Mannella, Riccardo and Wimberger, Sandro (2013) Noise assisted transport in the Wannier-Stark system. arXiv . (In Press)
http://arxiv.org/abs/1302.1602v1
oai:eprints.adm.unipi.it:1287
2013-09-10T14:48:40Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1287/
Quantum driving protocols for a two level system: from generalized Landau-Zener sweeps to superadiabatic control
Malossi, N.
Bason, M. G.
Viteau, M.
Arimondo, E.
Mannella, Riccardo
Morsch, O.
Ciampini, D.
FIS/03 - Fisica della materia
SUMMARY We present experimental results on the preparation of a desired quantum state
in a two-level system with the maximum possible fidelity using driving
protocols ranging from generalizations of the linear Landau-Zener protocol to
transitionless driving protocols that ensure perfect following of the
instantaneous adiabatic ground state. We also study the minimum time needed to
achieve a target fidelity and explore and compare the robustness of some of the
protocols against parameter variations simulating a possible experimental
uncertainty. In our experiments, we realize a two-level model system using
Bose-Einstein condensates inside optical lattices, but the results of our
investigation should hold for any quantum system that can be approximated by a
two-level system.
2012-11-07
Article
NonPeerReviewed
Malossi, N. and Bason, M. G. and Viteau, M. and Arimondo, E. and Mannella, Riccardo and Morsch, O. and Ciampini, D. (2012) Quantum driving protocols for a two level system: from generalized Landau-Zener sweeps to superadiabatic control. arXiv . (In Press)
oai:eprints.adm.unipi.it:1289
2013-09-10T15:06:21Z
oai:eprints.adm.unipi.it:1290
2013-07-30T10:52:52Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1290/
Wave Function Renormalization Effects in Resonantly Enhanced Tunneling
Lörch, N.
Pepe, F. V.
Lignier, H.
Ciampini, D.
Mannella, R.
Morsch, O.
Arimondo, E.
Facchi, P.
Florio, G.
Pascazio, S.
Wimberger, S.
FIS/03 - Fisica della materia
We study the time evolution of ultra-cold atoms in an accelerated optical
lattice. For a Bose- Einstein condensate with a narrow quasi-momentum
distribution in a shallow optical lattice the decay of the survival probability
in the ground band has a step-like structure. In this regime we establish a
connection between the wave function renormalization parameter Z introduced in
[Phys. Rev. Lett. 86, 2699 (2001)] to characterize non-exponential decay and
the phenomenon of resonantly enhanced tunneling, where the decay rate is peaked
for particular values of the lattice depth and the accelerating force.
American Physical Society
2012
Article
PeerReviewed
Lörch, N. and Pepe, F. V. and Lignier, H. and Ciampini, D. and Mannella, R. and Morsch, O. and Arimondo, E. and Facchi, P. and Florio, G. and Pascazio, S. and Wimberger, S. (2012) Wave Function Renormalization Effects in Resonantly Enhanced Tunneling. Physical review. A, Atomic, Molecular, and Optical Physics, 85 . 053602. ISSN 1094-1622
http://arxiv.org/abs/1201.6286v1
10.1103/PhysRevA.85.053602
oai:eprints.adm.unipi.it:1291
2013-07-30T10:51:25Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1291/
High-fidelity quantum driving
Bason, Mark G.
Viteau, Matthieu
Malossi, Nicola
Huillery, Paul
Arimondo, Ennio
Ciampini, Donatella
Fazio, Rosario
Giovannetti, Vittorio
Mannella, Riccardo
Morsch, Oliver
FIS/03 - Fisica della materia
SUMMARY The ability to accurately control a quantum system is a fundamental
requirement in many areas of modern science such as quantum information
processing and the coherent manipulation of molecular systems. It is usually
necessary to realize these quantum manipulations in the shortest possible time
in order to minimize decoherence, and with a large stability against
fluctuations of the control parameters. While optimizing a protocol for speed
leads to a natural lower bound in the form of the quantum speed limit rooted in
the Heisenberg uncertainty principle, stability against parameter variations
typically requires adiabatic following of the system. The ultimate goal in
quantum control is to prepare a desired state with 100% fidelity. Here we
experimentally implement optimal control schemes that achieve nearly perfect
fidelity for a two-level quantum system realized with Bose-Einstein condensates
in optical lattices. By suitably tailoring the time-dependence of the system's
parameters, we transform an initial quantum state into a desired final state
through a short-cut protocol reaching the maximum speed compatible with the
laws of quantum mechanics. In the opposite limit we implement the recently
proposed transitionless superadiabatic protocols, in which the system perfectly
follows the instantaneous adiabatic ground state. We demonstrate that
superadiabatic protocols are extremely robust against parameter variations,
making them useful for practical applications.
Nature
2012
Article
PeerReviewed
Bason, Mark G. and Viteau, Matthieu and Malossi, Nicola and Huillery, Paul and Arimondo, Ennio and Ciampini, Donatella and Fazio, Rosario and Giovannetti, Vittorio and Mannella, Riccardo and Morsch, Oliver (2012) High-fidelity quantum driving. Nature physics, 8 (2). pp. 147-152. ISSN 1745-2481
http://arxiv.org/abs/1111.1579v1
10.1038/nphys2170
oai:eprints.adm.unipi.it:1292
2013-07-30T10:45:56Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1292/
Engineering interband transport by time-dependent disorder
Tayebirad, Ghazal
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
We show how the evolution of atoms in a tilted lattice can be changed and
controlled by phase noise on the lattice. Dependent on the characteristic
parameters of the noise, the interband transport can either be suppressed or
enhanced, which is of interest for high precision control in experimental
realization with Bose-Einstein condensates. The effect of the noise on the
survival probability in the ground band is summarized in a scaling plot
stressing the universality of our results.
American Physical Society
2011
Article
PeerReviewed
Tayebirad, Ghazal and Mannella, Riccardo and Wimberger, Sandro (2011) Engineering interband transport by time-dependent disorder. Physical review. A, Atomic, Molecular, and Optical Physics, 84 . 031605. ISSN 1094-1622
http://arxiv.org/abs/1103.5066v2
10.1103/PhysRevA.84.031605
oai:eprints.adm.unipi.it:1294
2013-07-30T10:42:55Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1294/
Engineering of Landau-Zener tunneling
Tayebirad, Ghazal
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
Several ways are discussed how to control the Landau-Zener tunneling in the
Wannier-Stark system. We focus on a realization of this system with interacting
and noninteracting ultracold bosons. The tunneling from the ground band to the
continuum is shown to depend crucially on the initial condition and system
parameters and, more interestingly, on added timedependent disorder -- noise --
on the lattice beams.
2010-10-08
Article
NonPeerReviewed
Tayebirad, Ghazal and Mannella, Riccardo and Wimberger, Sandro (2010) Engineering of Landau-Zener tunneling. arXiv . (In Press)
http://arxiv.org/abs/1010.1671v1
10.1007/s00340-011-4430-6
oai:eprints.adm.unipi.it:1295
2013-09-10T14:50:55Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1295/
Time-resolved measurement of Landau--Zener tunneling in different bases
Tayebirad, G.
Zenesini, A.
Ciampini, D.
Mannella, Riccardo
Morsch, O.
Arimondo, E.
Lörch, N.
Wimberger, S.
FIS/03 - Fisica della materia
A comprehensive study of the tunneling dynamics of a Bose--Einstein
condensate in a tilted periodic potential is presented. We report numerical and
experimental results on time-resolved measurements of the Landau--Zener
tunneling of ultracold atoms introduced by the tilt, which experimentally is
realized by accelerating the lattice. The use of different protocols enables us
to access the tunneling probability, numerically as well as experimentally, in
two different bases, namely, the adiabatic basis and the diabatic basis. The
adiabatic basis corresponds to the eigenstates of the lattice, and the diabatic
one to the free-particle momentum eigenstates. Our numerical and experimental
results are compared with existing two-state Landau--Zener models.
American Physical Society
2010
Article
PeerReviewed
Tayebirad, G. and Zenesini, A. and Ciampini, D. and Mannella, Riccardo and Morsch, O. and Arimondo, E. and Lörch, N. and Wimberger, S. (2010) Time-resolved measurement of Landau--Zener tunneling in different bases. Physical review. A, Atomic, Molecular, and Optical Physics, 82 . 013633. ISSN 1094-1622
http://arxiv.org/abs/1007.1326v1
10.1103/PhysRevA.82.013633
oai:eprints.adm.unipi.it:1296
2013-07-30T10:37:03Z
7374617475733D7375626D6974746564
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1296/
Stochastic webs and quantum transport in superlattices: an introductory review
Soskin, S. M.
McClintock, P. V. E.
Fromhold, T. M.
Khovanov, I. A.
Mannella, R.
FIS/03 - Fisica della materia
SUMMARY Stochastic webs were discovered, first by Arnold for multi-dimensional
Hamiltonian systems, and later by Chernikov et al. for the low-dimensional
case. Generated by weak perturbations, they consist of thread-like regions of
chaotic dynamics in phase space. Their importance is that, in principle, they
enable transport from small energies to high energies. In this introductory
review, we concentrate on low-dimensional stochastic webs and on their
applications to quantum transport in semiconductor superlattices subject to
electric and magnetic fields. We also describe a recently-suggested
modification of the stochastic web to enhance chaotic transport through it and
we discuss its possible applications to superlattices. keywords: stochastic
webs; quantum transport; superlattices; separatrix chaos
2009-11-11
Article
NonPeerReviewed
Soskin, S. M. and McClintock, P. V. E. and Fromhold, T. M. and Khovanov, I. A. and Mannella, R. (2009) Stochastic webs and quantum transport in superlattices: an introductory review. arXiv . (Submitted)
http://arxiv.org/abs/0911.2167v1
oai:eprints.adm.unipi.it:1297
2013-09-10T14:50:13Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1297/
Self-gravitating Brownian particles in two dimensions: the case of N=2 particles
Chavanis, P. H.
Mannella, Riccardo
FIS/03 - Fisica della materia
SUMMARY We study the motion of N=2 overdamped Brownian particles in gravitational
interaction in a space of dimension d=2. This is equivalent to the simplified
motion of two biological entities interacting via chemotaxis when time delay
and degradation of the chemical are ignored. This problem also bears some
similarities with the stochastic motion of two point vortices in viscous
hydrodynamics [Agullo & Verga, Phys. Rev. E, 63, 056304 (2001)]. We
analytically obtain the density probability of finding the particles at a
distance r from each other at time t. We also determine the probability that
the particles have coalesced and formed a Dirac peak at time t (i.e. the
probability that the reduced particle has reached r=0 at time t). Finally, we
investigate the variance of the distribution <r^2> and discuss the proper form
of the virial theorem for this system. The reduced particle has a normal
diffusion behaviour for small times with a gravity-modified diffusion
coefficient <r^2>=r_0^2+(4k_B/\xi\mu)(T-T_*)t, where k_BT_{*}=Gm_1m_2/2 is a
critical temperature, and an anomalous diffusion for large times
<r^2>~t^(1-T_*/T). As a by-product, our solution also describes the growth of
the Dirac peak (condensate) that forms in the post-collapse regime of the
Smoluchowski-Poisson system (or Keller-Segel model) for T<T_c=GMm/(4k_B). We
find that the saturation of the mass of the condensate to the total mass is
algebraic in an infinite domain and exponential in a bounded domain.
Springer
2010
Article
PeerReviewed
Chavanis, P. H. and Mannella, Riccardo (2010) Self-gravitating Brownian particles in two dimensions: the case of N=2 particles. European Physical Journal B - Condensed Matter and Complex Systems, 78 . p. 139. ISSN 1434-6036
http://arxiv.org/abs/0911.1022v2
oai:eprints.adm.unipi.it:1298
2013-07-30T10:28:03Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1298/
Maximal width of the separatrix chaotic layer
Soskin, S. M.
Mannella, R.
FIS/03 - Fisica della materia
SUMMARY The main goal of the paper is to find the {\it absolute maximum} of the width
of the separatrix chaotic layer as function of the frequency of the
time-periodic perturbation of a one-dimensional Hamiltonian system possessing a
separatrix, which is one of the major unsolved problems in the theory of
separatrix chaos. For a given small amplitude of the perturbation, the width is
shown to possess sharp peaks in the range from logarithmically small to
moderate frequencies. These peaks are universal, being the consequence of the
involvement of the nonlinear resonance dynamics into the separatrix chaotic
motion. Developing further the approach introduced in the recent paper by
Soskin et al. ({\it PRE} {\bf 77}, 036221 (2008)), we derive leading-order
asymptotic expressions for the shape of the low-frequency peaks. The maxima of
the peaks, including in particular the {\it absolute maximum} of the width, are
proportional to the perturbation amplitude times either a logarithmically large
factor or a numerical, still typically large, factor, depending on the type of
system. Thus, our theory predicts that the maximal width of the chaotic layer
may be much larger than that predicted by former theories. The theory is
verified in simulations. An application to the facilitation of global chaos
onset is discussed.
2009-08-04
Article
NonPeerReviewed
Soskin, S. M. and Mannella, R. (2009) Maximal width of the separatrix chaotic layer. arXiv .
http://arxiv.org/abs/0908.0459v1
oai:eprints.adm.unipi.it:1299
2013-07-30T10:30:24Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D626F6F6B5F73656374696F6E
http://eprints.adm.unipi.it/1299/
A New Approach To The Treatment Of Separatrix Chaos And Its Applications
Soskin, S. M.
Mannella, R.
Yevtushenko, O. M.
Khovanov, I. A.
McClintock, P. V. E.
FIS/03 - Fisica della materia
SUMMARY We consider time-periodically perturbed 1D Hamiltonian systems possessing one
or more separatrices. If the perturbation is weak, then the separatrix chaos is
most developed when the perturbation frequency lies in the logarithmically
small or moderate ranges: this corresponds to the involvement of resonance
dynamics into the separatrix chaos. We develop a method matching the discrete
chaotic dynamics of the separatrix map and the continuous regular dynamics of
the resonance Hamiltonian. The method has allowed us to solve the long-standing
problem of an accurate description of the maximum of the separatrix chaotic
layer width as a function of the perturbation frequency. It has also allowed us
to predict and describe new phenomena including, in particular: (i) a drastic
facilitation of the onset of global chaos between neighbouring separatrices,
and (ii) a huge increase in the size of the low-dimensional stochastic web.
Springer
2010
Book Section
PeerReviewed
Soskin, S. M. and Mannella, R. and Yevtushenko, O. M. and Khovanov, I. A. and McClintock, P. V. E. (2010) A New Approach To The Treatment Of Separatrix Chaos And Its Applications. In: Hamiltonian Chaos Beyond the KAM Theory. Springer, pp. 51-141. ISBN 978-3-642-12718-2
http://arxiv.org/abs/0906.3444v1
oai:eprints.adm.unipi.it:1300
2013-07-30T10:37:40Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1300/
Time-resolved measurement of Landau-Zener tunneling in periodic potentials
Zenesini, A.
Lignier, H.
Tayebirad, G.
Radogostowicz, J.
Ciampini, D.
Mannella, R.
Wimberger, S.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
SUMMARY We report time-resolved measurements of Landau-Zener tunneling of
Bose-Einstein condensates in accelerated optical lattices, clearly resolving
the step-like time dependence of the band populations. Using different
experimental protocols we were able to measure the tunneling probability both
in the adiabatic and in the diabatic bases of the system. We also
experimentally determine the contribution of the momentum width of the Bose
condensates to the width of the tunneling steps and discuss the implications
for measuring the jump time in the Landau-Zener problem.
2009-03-19
Article
NonPeerReviewed
Zenesini, A. and Lignier, H. and Tayebirad, G. and Radogostowicz, J. and Ciampini, D. and Mannella, R. and Wimberger, S. and Morsch, O. and Arimondo, E. (2009) Time-resolved measurement of Landau-Zener tunneling in periodic potentials. arXiv . (In Press)
http://arxiv.org/abs/0903.3345v1
oai:eprints.adm.unipi.it:1301
2013-07-30T10:38:10Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1301/
Resonant tunneling of Bose-Einstein condensates in optical lattices
Zenesini, Alessandro
Sias, Carlo
Lignier, Hans
Singh, Yeshpal
Ciampini, Donatella
Morsch, Oliver
Mannella, Riccardo
Arimondo, Ennio
Tomadin, Andrea
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY In this article, we present theoretical as well as experimental results on
resonantly enhanced tunneling of Bose-Einstein condensates in optical lattices
both in the linear case and for small nonlinearities. Our results demonstrate
the usefulness of condensates in optical lattices for simulating Hamiltonians
originally used for describing solid state phenomena.
IOPScience
2008
Article
PeerReviewed
Zenesini, Alessandro and Sias, Carlo and Lignier, Hans and Singh, Yeshpal and Ciampini, Donatella and Morsch, Oliver and Mannella, Riccardo and Arimondo, Ennio and Tomadin, Andrea and Wimberger, Sandro (2008) Resonant tunneling of Bose-Einstein condensates in optical lattices. New Journal of Physics, 10 . 053038. ISSN 1367-2630
http://arxiv.org/abs/0712.3866v2
10.1088/1367-2630/10/5/053038
oai:eprints.adm.unipi.it:1302
2013-07-30T10:38:45Z
7374617475733D696E7072657373
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1302/
Separatrix chaos: new approach to the theoretical treatment
Soskin, S. M.
Mannella, R.
Yevtushenko, O. M.
FIS/03 - Fisica della materia
SUMMARY We develop a new approach to the theoretical treatment of the separatrix
chaos, using a special analysis of the separatrix map. The approach allows us
to describe boundaries of the separatrix chaotic layer in the Poincar\'{e}
section and transport within the layer. We show that the maximum which the
width of the layer in energy takes as the perturbation frequency varies is much
larger than the perturbation amplitude, in contrast to predictions by earlier
theories suggesting that the maximum width is of the order of the amplitude.
The approach has also allowed us to develop the self-consistent theory of the
earlier discovered (PRL 90, 174101 (2003)) drastic facilitation of the onset of
global chaos between adjacent separatrices. Simulations agree with the theory.
2007-11-29
Article
NonPeerReviewed
Soskin, S. M. and Mannella, R. and Yevtushenko, O. M. (2007) Separatrix chaos: new approach to the theoretical treatment. arXiv . (In Press)
http://arxiv.org/abs/0711.4827v1
oai:eprints.adm.unipi.it:1303
2013-07-30T09:01:03Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1303/
Many-body Landau-Zener tunneling in the Bose-Hubbard model
Tomadin, Andrea
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY We study a model for ultracold, spinless atoms in quasi-one dimensional
optical lattices and subjected to a tunable tilting force. Statistical tests
are employed to quantitatively characterize the spectrum of the Floquet-Bloch
operator of the system along the transition from the regular to the quantum
chaotic regime. Moreover, we perturbatively include the coupling of the
one-band model to the second energy band. This allows us to study the
Landau-Zener interband tunneling within a truly many-body description of
ultracold atoms. The distributions of the computed tunneling rates provide an
independent and experimentally accessible signature of the regular-chaotic
transition.
American Physical Society
2008
Article
PeerReviewed
Tomadin, Andrea and Mannella, Riccardo and Wimberger, Sandro (2008) Many-body Landau-Zener tunneling in the Bose-Hubbard model. Physical review. A, Atomic, Molecular, and Optical Physics, 77 . 013606. ISSN 1094-1622
http://arxiv.org/abs/0711.3230v1
10.1103/PhysRevA.77.013606
oai:eprints.adm.unipi.it:1304
2013-07-30T09:02:18Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1304/
Engineered quantum tunnelling in extended periodic potentials
Wimberger, Sandro
Ciampini, Donatella
Morsch, Oliver
Mannella, Riccardo
Arimondo, Ennio
FIS/03 - Fisica della materia
Quantum tunnelling from a tilted, but otherwise periodic potential is
studied. Our theoretical and experimental results show that, by controlling the
system's parameters, we can engineer the escape rate of a Bose-Einstein
condensate to an exceptional degree. Possible applications of this atom-optics
realization of the open Wannier-Stark system are discussed.
IOPScience
2007
Article
PeerReviewed
Wimberger, Sandro and Ciampini, Donatella and Morsch, Oliver and Mannella, Riccardo and Arimondo, Ennio (2007) Engineered quantum tunnelling in extended periodic potentials. Journal of physics: conference series, 67 (012060). ISSN 1742-6596
http://arxiv.org/abs/0706.0414v1
10.1088/1742-6596/67/1/012060
oai:eprints.adm.unipi.it:1305
2013-07-30T08:32:35Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1305/
Many-body interband tunneling as a witness for complex dynamics in the Bose-Hubbard model
Tomadin, Andrea
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY A perturbative model is studied for the tunneling of many-particle states from the ground band to the first excited energy band, mimicking Landau-Zener decay for ultracold, spinless atoms in quasi-one dimensional optical lattices subjected to a tunable tilting force. The distributions of the computed tunneling rates provide an independent and experimentally accessible signature
of the regular-chaotic transition in the strongly correlated many-body dynamics of the ground band.
American Physical Society
2007-04
Article
PeerReviewed
Tomadin, Andrea and Mannella, Riccardo and Wimberger, Sandro (2007) Many-body interband tunneling as a witness for complex dynamics in the Bose-Hubbard model. Physical review letters, 98 (13). p. 130402. ISSN 0031-9007
http://arxiv.org/abs/0704.0233v1
10.1103/PhysRevLett.98.130402
oai:eprints.adm.unipi.it:1308
2013-08-06T08:42:51Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1308/
Dynamical symmetries and harmonic generation
Ceccherini, F.
Bauer, D.
Cornolti, F.
FIS/01 - Fisica sperimentale
SUMMARY We discuss harmonic generation in the case of laser field-dressed
Hamiltonians that are invariant under so-called dynamical symmetry operations.
Examples for such systems are molecules which exhibit a discrete rotational
symmetry of order
N (e.g. benzene with N=6) interacting with a circularly polarized laser field
and single atoms in a bichromatic field, with the two lasers having circular
polarizations. Within a general group theory approach we study the harmonics
one obtains from the interaction of a laser pulse and a circular molecule. When
the system is in a pure field-dressed state the known selection rule kN \pm 1,
k=1,2,3, ... results. However, other lines are observed when recombinations
with states of a symmetry different from the initial one become important. This
is the case for realistic laser pulses (i.e., with a finite duration). In
particular when the fundamental laser frequency (or one of its multiples) is
resonant with a transition between field-dressed states. Numerical ab initio
simulations, confirming our analytical calculations and illustrating the power
of the group theory approach, are presented.
IOPScience
2001-07-12
Article
PeerReviewed
Ceccherini, F. and Bauer, D. and Cornolti, F. (2001) Dynamical symmetries and harmonic generation. Journal of physics B, Atomic, molecular and optical physics, 34 . p. 5017. ISSN 1361-6455
http://arxiv.org/abs/physics/0107024v2
10.1088/0953-4075/34/24/305
oai:eprints.adm.unipi.it:1309
2013-08-06T08:37:10Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1309/
Harmonic generation by atoms in circularly polarized two-color laser fields with coplanar polarizations and commensurate frequencies
Ceccherini, F.
Bauer, D.
Cornolti, F.
FIS/01 - Fisica sperimentale
SUMMARY The generation of harmonics by atoms or ions in a two-color, coplanar field
configuration with commensurate frequencies is investigated through both, an
analytical calculation based on the Lewenstein model and the numerical ab
initio solution of the time-dependent Schroedinger equation of a
two-dimensional model ion. Through the analytical model, selection rules for
the harmonic orders in this field configuration, a generalized cut-off for the
harmonic spectra, and an integral expression for the harmonic dipole strength
is provided. The numerical results are employed to test the predictions of the
analytical model. The scaling of the cut-off as a function of both, one of the
laser intensities and frequency ratio $\eta$, as well as entire spectra for
different $\eta$ and laser intensities are presented and analyzed. The
theoretical cut-off is found to be an upper limit for the numerical results.
Other discrepancies between analytical model and numerical results are
clarified by taking into account the probabilities of the absorption processes
involved.
American Physical Society
2002-11-27
Article
PeerReviewed
Ceccherini, F. and Bauer, D. and Cornolti, F. (2002) Harmonic generation by atoms in circularly polarized two-color laser fields with coplanar polarizations and commensurate frequencies. Physical review. A, Atomic, Molecular, and Optical Physics, 68 . 053402 . ISSN 1094-1622
http://arxiv.org/abs/physics/0211110v1
10.1103/PhysRevA.68.053402
oai:eprints.adm.unipi.it:1310
2013-08-06T08:32:02Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1310/
Non-perturbative features of driven scattering systems
Cintio, Andrea
Cornolti, Fulvio
FIS/01 - Fisica sperimentale
SUMMARY We investigate the scattering properties of one-dimensional, periodically and
non-periodically forced oscillators. The pattern of singularities of the
scattering function, in the periodic case, shows a characteristic hierarchical
structure where the number Nc of zeros of the solutions plays the role of an
order parameter marking the level of the observed self-similar structure. The
behavior is understood both in terms of the return map and of the intersections
pattern of the invariant manifolds of the outermost fixed points. In the
non-periodic case the scattering function does not provide a complete
development of the hierarchical structure. The singularities pattern of the
outgoing energy as a function of the driver amplitude is connected to the
arrangement of gaps in the fundamental regions. The survival probability
distribution of temporarily bound orbits is shown to decay asymptotically as a
power law. The "stickiness" of regular regions of phase space, given by KAM
surfaces and remnant of KAM curves, is responsible for this observation.
2012-06-09
Article
NonPeerReviewed
Cintio, Andrea and Cornolti, Fulvio (2012) Non-perturbative features of driven scattering systems. arXiv .
http://arxiv.org/abs/1206.1922v1
oai:eprints.adm.unipi.it:1311
2013-08-06T08:17:27Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1311/
"Single-cycle" ionization effects in laser-matter interaction
Jarque, E. Conejero
Cornolti, F.
Macchi, A.
Ruhl, H.
FIS/01 - Fisica sperimentale
SUMMARY We investigate numerically effects related to ''single-cycle'' ionization of
dense matter by an ultra-short laser pulse. The strongly non-adiabatic response
of electrons leads to generation of a megagauss steady magnetic field in
laser-solid interaction. By using two-beam interference, it is possible to
create periodic density structures able to trap light and to generate
relativistic ionization fronts
Cambridge University Press
2000-02-08
Article
PeerReviewed
Jarque, E. Conejero and Cornolti, F. and Macchi, A. and Ruhl, H. (2000) "Single-cycle" ionization effects in laser-matter interaction. Laser and Particle Beams, 18 (3). pp. 411-416. ISSN 1469-803X
http://arxiv.org/abs/physics/0002017v1
10.1017/S0263034600183090
oai:eprints.adm.unipi.it:1312
2013-08-06T08:17:47Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1312/
Two-Surface Wave Decay
Macchi, Andrea
Cornolti, Fulvio
Pegoraro, Francesco
FIS/01 - Fisica sperimentale
SUMMARY Using an analytical model we discuss the parametric excitation of pairs of
electron surface waves (ESW) in the interaction of an ultrashort, intense laser
pulse with an overdense plasma which has a step-like density profile. The ESWs
can be excited either by the electric or by the magnetic part of the Lorentz
force exerted by the laser and, correspondingly, have frequencies around
$\omega/2$ or $\omega$, where $\omega$ is the laser frequency.
American Institute of Physics
2002
Article
PeerReviewed
Macchi, Andrea and Cornolti, Fulvio and Pegoraro, Francesco (2002) Two-Surface Wave Decay. PHYSICS OF PLASMAS, 9 (5). p. 1704. ISSN 1089-7674
http://arxiv.org/abs/physics/0105017v4
10.1063/1.1464146
oai:eprints.adm.unipi.it:1313
2013-08-05T10:42:53Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1313/
C$_{60}$ in intense femtosecond laser pulses: nonlinear dipole response and ionization
Bauer, D.
Ceccherini, F.
Macchi, A.
Cornolti, F.
FIS/01 - Fisica sperimentale
SUMMARY We study the interaction of strong femtosecond laser pulses with the C$_{60}$
molecule employing time-dependent density functional theory with the ionic
background treated in a jellium approximation. The laser intensities considered
are below the threshold of strong fragmentation but too high for perturbative
treatments such as linear response. The nonlinear response of the model to
excitations by short pulses of frequencies up to 45eV is presented and analyzed
with the help of Kohn-Sham orbital resolved dipole spectra. In femtosecond
laser pulses of 800nm wavelength ionization is found to occur multiphoton-like
rather than via excitation of a ``giant'' resonance.
American Physical Society
2001-06-14
Article
PeerReviewed
Bauer, D. and Ceccherini, F. and Macchi, A. and Cornolti, F. (2001) C$_{60}$ in intense femtosecond laser pulses: nonlinear dipole response and ionization. Physical review. A, Atomic, Molecular, and Optical Physics, 64 (6). 063203 . ISSN 1094-1622
http://arxiv.org/abs/physics/0106044v3
10.1103/PhysRevA.64.063203
oai:eprints.adm.unipi.it:1314
2013-08-05T10:45:20Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1314/
Two-surface wave decay: improved analytical theory and effects on electron acceleration
Macchi, A.
Battaglini, M.
Cattani, F.
Cornolti, F.
FIS/01 - Fisica sperimentale
SUMMARY Two-surface wave decay (TSWD), i.e. the parametric excitation of electron
surface waves, was recently proposed as an absorption mechanism in the
interaction of ultrashort, intense laser pulses with solid targets. We present
an extension of the fluid theory of TSWD to a warm plasma which treats boundary
effects consistently. We also present test-particle simulations showing
localized enhancement of electron acceleration by TSWD fields; this effect
leads to a modulation of the current density entering into the target and may
seed current filamentation instabilities.
Springer
2003-10-23
Article
PeerReviewed
Macchi, A. and Battaglini, M. and Cattani, F. and Cornolti, F. (2003) Two-surface wave decay: improved analytical theory and effects on electron acceleration. Applied Physics B, 78 (7-8). pp. 915-918. ISSN 1432-0649
http://arxiv.org/abs/physics/0310119v2
10.1007/s00340-004-1444-3
oai:eprints.adm.unipi.it:1315
2013-08-06T08:17:37Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1315/
Harmonic generation by atoms in circularly polarized laser fields: far-off and near resonances regimes
Ceccherini, F.
Davini, N.
Bauer, D.
Cornolti, F.
FIS/01 - Fisica sperimentale
SUMMARY The generation of harmonics by atoms interacting with two circularly
polarized and frequency related laser fields is addressed through ab initio
numerical simulations. A detailed charaterization of a few specific harmonics
is given. In particular, the two different cases where the total energy
absorbed through photons is far-off or close to the energy gap between
different atomic states are investigated. It is found that the conversion
efficiency in the harmonic generation is strongly dependent on the inner atomic
structure and in certain specific cases it can be significantly enhanced within
a small frequency range.
Springer
2003-11-07
Article
PeerReviewed
Ceccherini, F. and Davini, N. and Bauer, D. and Cornolti, F. (2003) Harmonic generation by atoms in circularly polarized laser fields: far-off and near resonances regimes. Applied Physics B, 78 (7-8). pp. 851-854. ISSN 1432-0649
http://arxiv.org/abs/physics/0311032v1
10.1007/s00340-004-1458-x
oai:eprints.adm.unipi.it:1316
2013-08-06T09:09:15Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1316/
Expansion of a finite size plasma in vacuum
Betti, S.
Ceccherini, F.
Cornolti, F.
Pegoraro, F.
FIS/01 - Fisica sperimentale
SUMMARY The expansion dynamics of a finite size plasma is examined from an analytical
perspective. Results regarding the charge distribution as well as the
electrostatic potential are presented. The acceleration of the ions and the
associated cooling of the electrons that takes place during the plasma
expansion is described. An extensive analysis of the transition between the
semi infinite and the finite size plasma behaviour is carried out. Finally, a
test of the analytical results, performed through numerical simulations, is
presented.
IOP Publishing
2005
Article
PeerReviewed
Betti, S. and Ceccherini, F. and Cornolti, F. and Pegoraro, F. (2005) Expansion of a finite size plasma in vacuum. Plasma Physics and Controlled Fusion, 47 . p. 521. ISSN 1361-6587
http://arxiv.org/abs/physics/0405030v1
10.1088/0741-3335/47/3/008
oai:eprints.adm.unipi.it:1317
2013-08-06T08:52:53Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1317/
Charged State of a Spherical Plasma in Vacuum
Cornolti, F.
Ceccherini, F.
Betti, S.
Pegoraro, F.
FIS/01 - Fisica sperimentale
SUMMARY The stationary state of a spherically symmetric plasma configuration is
investigated in the limit of immobile ions and weak collisions. Configurations
with small radii are positively charged as a significant fraction of the
electron population evaporates during the equilibration process, leaving behind
an electron distribution function with an energy cutoff. Such charged plasma
configurations are of interest for the study of Coulomb explosions and ion
acceleration from small clusters irradiated by ultraintense laser pulses and
for the investigation of ion bunches propagation in a plasma.
American Physical Society
2004-11-05
Article
PeerReviewed
Cornolti, F. and Ceccherini, F. and Betti, S. and Pegoraro, F. (2004) Charged State of a Spherical Plasma in Vacuum. Physical review. E, Statistical, nonlinear, and soft matter physics, 71 (056407). ISSN 1550-2376
http://arxiv.org/abs/physics/0411051v1
10.1103/PhysRevE.71.056407
oai:eprints.adm.unipi.it:1318
2013-08-06T08:46:35Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1318/
Electric field dynamics and ion acceleration in the self-channeling of a superintense laser pulse
Macchi, A.
Ceccherini, F.
Cornolti, F.
Kar, S.
Borghesi, M.
FIS/01 - Fisica sperimentale
SUMMARY The dynamics of electric field generation and radial acceleration of ions by
a laser pulse of relativistic intensity propagating in an underdense plasma has
been investigated using an one-dimensional electrostatic, ponderomotive model
developed to interpret experimental measurements of electric fields [S. Kar et
al, New J. Phys. *9*, 402 (2007)]. Ions are spatially focused at the edge of
the charge-displacement channel, leading to hydrodynamical breaking, which in
turns causes the heating of electrons and an "echo" effect in the electric
field. The onset of complete electron depletion in the central region of the
channel leads to a smooth transition to a "Coulomb explosion" regime and a
saturation of ion acceleration.
2007-01-11
Article
NonPeerReviewed
Macchi, A. and Ceccherini, F. and Cornolti, F. and Kar, S. and Borghesi, M. (2007) Electric field dynamics and ion acceleration in the self-channeling of a superintense laser pulse. arXiv .
http://arxiv.org/abs/physics/0701139v4
oai:eprints.adm.unipi.it:1319
2013-08-06T08:44:39Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1319/
Collective Absorption Dynamics and Enhancement in Deformed Targets
Ruhl, Hartmut
Mulser, Peter
Hain, Steffen
Cornolti, Fulvio
Macchi, Andrea
FIS/01 - Fisica sperimentale
SUMMARY The interaction of intense fs laser pulses with thin foils that have an
imposed deformation is compared with thick targets that develop bow shocks.
Both target types yield good absorption. Up to 80% absorption is obtained for a
$0.2\mu m$ thick, 15 times over-dense foil at $4 \cdot 10^{18} W/cm^2$. A value
of 50% is obtained for a $4 \mu m$ thick, 2 times over-dense thick target at
$10^{18} W/cm^2$. For comparable extension and curvature of the laser-plasma
interfaces absorption levels in both targets become similar. In both absorption
scales weakly with intensity and density. Energy transport in thin foils and
thick targets, however, is different.
1998-08-27
Article
NonPeerReviewed
Ruhl, Hartmut and Mulser, Peter and Hain, Steffen and Cornolti, Fulvio and Macchi, Andrea (1998) Collective Absorption Dynamics and Enhancement in Deformed Targets. arXiv .
http://arxiv.org/abs/physics/9808039v2
oai:eprints.adm.unipi.it:1320
2013-08-06T08:18:40Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1320/
Laser acceleration of ion bunches at the front surface of overdense plasmas
Macchi, Andrea
Cattani, Federica
Liseykina, Tatiana V.
Cornolti, Fulvio
FIS/01 - Fisica sperimentale
SUMMARY The acceleration of ions in the interaction of high intensity laser pulses
with overdense plasmas is investigated with particle-in-cell simulations. For
circular polarization of the laser pulses, high-density ion bunches moving into
the plasma are generated at the laser-plasma interaction surface. A simple
analytical model accounts for the numerical observations and provides scaling
laws for the ion bunch energy and generation time as a function of pulse
intensity and plasma density.
American Physical Society
2005
Article
PeerReviewed
Macchi, Andrea and Cattani, Federica and Liseykina, Tatiana V. and Cornolti, Fulvio (2005) Laser acceleration of ion bunches at the front surface of overdense plasmas. Physical review letters, 94 . p. 165003. ISSN 0031-9007
http://arxiv.org/abs/physics/0411023v2
10.1103/PhysRevLett.94.165003
oai:eprints.adm.unipi.it:1321
2013-08-06T08:18:18Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1321/
Surface Oscillations in Overdense Plasmas Irradiated by Ultrashort Laser Pulses
Macchi, A.
Cornolti, F.
Pegoraro, F.
Liseikina, T. V.
Ruhl, H.
Vshivkov, V. A.
FIS/01 - Fisica sperimentale
SUMMARY The generation of electron surface oscillations in overdense plasmas
irradiated at normal incidence by an intense laser pulse is investigated.
Two-dimensional (2D) particle-in-cell simulations show a transition from a
planar, electrostatic oscillation at $2\omega$, with $\omega$ the laser
frequency, to a 2D electromagnetic oscillation at frequency $\omega$ and
wavevector $k>\omega/c$. A new electron parametric instability, involving the
decay of a 1D electrostatic oscillation into two surface waves, is introduced
to explain the basic features of the 2D oscillations. This effect leads to the
rippling of the plasma surface within a few laser cycles, and is likely to have
a strong impact on laser interaction with solid targets.
American Physical Society
2001
Article
PeerReviewed
Macchi, A. and Cornolti, F. and Pegoraro, F. and Liseikina, T. V. and Ruhl, H. and Vshivkov, V. A. (2001) Surface Oscillations in Overdense Plasmas Irradiated by Ultrashort Laser Pulses. Physical review letters, 87 . p. 205004. ISSN 0031-9007
http://arxiv.org/abs/physics/0105019v3
10.1103/PhysRevLett.87.205004
oai:eprints.adm.unipi.it:1322
2013-08-06T08:18:31Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1322/
Ion dynamics and coherent structure formation following laser pulse self-channeling
Macchi, Andrea
Bigongiari, Alessandra
Ceccherini, Francesco
Cornolti, Fulvio
Liseikina, Tatiana V.
Borghesi, Marco
Kar, Satyabrata
Romaganani, Lorenzo
FIS/01 - Fisica sperimentale
SUMMARY The propagation of a superintense laser pulse in an underdense, inhomogeneous
plasma has been studied numerically by two-dimensional particle-in-cell
simulations on a time scale extending up to several picoseconds. The effects of
the ion dynamics following the charge-displacement self-channeling of the laser
pulse have been addressed. Radial ion acceleration leads to the ``breaking'' of
the plasma channel walls, causing an inversion of the radial space-charge field
and the filamentation of the laser pulse. At later times a number of
long-lived, quasi-periodic field structures are observed and their dynamics is
characterized with high resolution. Inside the plasma channel, a pattern of
electric and magnetic fields resembling both soliton- and vortex-like
structures is observed.
IOP Publishing
2007-08-21
Article
PeerReviewed
Macchi, Andrea and Bigongiari, Alessandra and Ceccherini, Francesco and Cornolti, Fulvio and Liseikina, Tatiana V. and Borghesi, Marco and Kar, Satyabrata and Romaganani, Lorenzo (2007) Ion dynamics and coherent structure formation following laser pulse self-channeling. Plasma Physics and Controlled Fusion . ISSN 1361-6587
http://arxiv.org/abs/0708.2780v1
10.1088/0741-3335/49/12B/S05
oai:eprints.adm.unipi.it:1323
2013-08-06T08:18:00Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3031
74797065733D61727469636C65
http://eprints.adm.unipi.it/1323/
Generation and Observation of Coherent, Long--Lived Structures in a Laser--Plasma Channel
Liseykina, T. V.
Ceccherini, F.
Cornolti, F.
Echkina, E. Yu.
Macchi, A.
Pegoraro, F.
Borghesi, M.
Kar, S.
Romagnani, L.
Bulanov, S. V.
Willi, O.
Galimberti, M.
FIS/01 - Fisica sperimentale
SUMMARY In recent experiments of laser pulse interaction at relativistic intensities
with a low density plasma, the proton radiography technique showed evidence of
long--lived field structures generated after the self-channeling of the laser
pulse. We present 2D particle-in-cell simulations of this interaction regime,
where the dynamics of similar structures has been resolved with high temporal
and spatial resolution. An axially symmetrical field pattern, resembling both
soliton-like and vortex structures, has been observed. A study of the physics
of such structures and a comparison with experimental data is in progress.
2007-02-21
Article
NonPeerReviewed
Liseykina, T. V. and Ceccherini, F. and Cornolti, F. and Echkina, E. Yu. and Macchi, A. and Pegoraro, F. and Borghesi, M. and Kar, S. and Romagnani, L. and Bulanov, S. V. and Willi, O. and Galimberti, M. (2007) Generation and Observation of Coherent, Long--Lived Structures in a Laser--Plasma Channel. arXiv .
http://arxiv.org/abs/physics/0702177v1
oai:eprints.adm.unipi.it:1348
2015-04-07T15:40:58Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1348/
Bloch oscillations and mean-field effects of Bose-Einstein condensates
in 1-D optical lattices
Morsch, O.
Müller, J. H.
Cristiani, M.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We have loaded Bose-Einstein condensates into one-dimensional, off-resonant
optical lattices and accelerated them by chirping the frequency difference
between the two lattice beams. For small values of the lattice well-depth,
Bloch oscillations were observed. Reducing the potential depth further,
Landau-Zener tunneling out of the lowest lattice band, leading to a breakdown
of the oscillations, was also studied and used as a probe for the effective
potential resulting from mean-field interactions as predicted by Choi and Niu
[Phys. Rev. Lett. {\bf 82}, 2022 (1999)]. The effective potential was measured
for various condensate densities and trap geometries, yielding good qualitative
agreement with theoretical calculations.
American Physical Society
Article
PeerReviewed
Morsch, O. and Müller, J. H. and Cristiani, M. and Ciampini, D. and Arimondo, E. Bloch oscillations and mean-field effects of Bose-Einstein condensates in 1-D optical lattices. Physical review letters (140402). ISSN 0031-9007
http://arxiv.org/abs/cond-mat/0108457v1
10.1103/PhysRevLett.87.140402
oai:eprints.adm.unipi.it:1349
2015-04-07T15:34:55Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1349/
Experimental properties of Bose-Einstein condensates in 1D optical
lattices: Bloch oscillations, Landau-Zener tunneling and mean-field effects
Cristiani, M.
Morsch, O.
Müller, J. H.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We report experimental results on the properties of Bose-Einstein condensates
in 1D optical lattices. By accelerating the lattice, we observed Bloch
oscillations of the condensate in the lowest band, as well as Landau-Zener
(L-Z) tunneling into higher bands when the lattice depth was reduced and/or the
acceleration of the lattice was increased. The dependence of the L-Z tunneling
rate on the condensate density was then related to mean-field effects modifying
the effective potential acting on the condensate, yielding good agreement with
recent theoretical work. We also present several methods for measuring the
lattice depth and discuss the effects of the micromotion in the TOP-trap on our
experimental results.
American Physical Society
2002-02-04
Article
PeerReviewed
Cristiani, M. and Morsch, O. and Müller, J. H. and Ciampini, D. and Arimondo, E. (2002) Experimental properties of Bose-Einstein condensates in 1D optical lattices: Bloch oscillations, Landau-Zener tunneling and mean-field effects. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0202053v1
10.1103/PhysRevA.65.063612
oai:eprints.adm.unipi.it:1350
2015-04-07T15:34:18Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1350/
Free expansion of a Bose-Einstein condensate in a 1D optical lattice
Morsch, O.
Cristiani, M.
Müller, J. H.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We have experimentally investigated the free expansion of a Bose-Einstein
condensate in an array of two-dimensional traps created by a one-dimensional
optical lattice. If the condensate held in a magnetic trap is loaded
adiabatically into the lattice, the increase in chemical potential due to the
additional periodic potential is reflected in the expansion of the condensate
after switching off the magnetic trap. We have calculated the chemical
potential from measurements of the transverse expansion of the condensate as a
function of the lattice parameters.
American Physical Society
2002-04-24
Article
PeerReviewed
Morsch, O. and Cristiani, M. and Müller, J. H. and Ciampini, D. and Arimondo, E. (2002) Free expansion of a Bose-Einstein condensate in a 1D optical lattice. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0204528v2
10.1103/PhysRevA.66.021601
oai:eprints.adm.unipi.it:1357
2015-04-08T09:17:44Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1357/
Resonantly enhanced tunneling of Bose-Einstein condensates in periodic potentials
Sias, C.
Zenesini, A.
Lignier, H.
Wimberger, S.
Ciampini, D.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report on measurements of resonantly enhanced tunneling of Bose-Einstein
condensates loaded into an optical lattice. By controlling the initial
conditions of our system we were able to observe resonant tunneling in the
ground and the first two excited states of the lattice wells. We also
investigated the effect of the intrinsic nonlinearity of the condensate on the
tunneling resonances.
American Physical Society
2007-02-23
Article
PeerReviewed
Sias, C. and Zenesini, A. and Lignier, H. and Wimberger, S. and Ciampini, D. and Morsch, O. and Arimondo, E. (2007) Resonantly enhanced tunneling of Bose-Einstein condensates in periodic potentials. Physical review letters . ISSN 0031-9007
http://arxiv.org/abs/cond-mat/0702552v1
oai:eprints.adm.unipi.it:1358
2015-04-07T15:41:32Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1358/
Photoionization of ultracold and Bose-Einstein condensed Rb atoms
Ciampini, D.
Anderlini, M.
Müller, J. H.
Fuso, F.
Morsch, O.
Thomsen, J. W.
Arimondo, E.
FIS/03 - Fisica della materia
Photoionization of a cold atomic sample offers intriguing possibilities to
observe collective effects at extremely low temperatures. Irradiation of a
rubidium condensate and of cold rubidium atoms within a magneto-optical trap
with laser pulses ionizing through 1-photon and 2-photon absorption processes
has been performed. Losses and modifications in the density profile of the
remaining trapped cold cloud or the remaining condensate sample have been
examined as function of the ionizing laser parameters. Ionization
cross-sections were measured for atoms in a MOT, while in magnetic traps losses
larger than those expected for ionization process were measured.
American Physical Society
2002-06-07
Article
PeerReviewed
Ciampini, D. and Anderlini, M. and Müller, J. H. and Fuso, F. and Morsch, O. and Thomsen, J. W. and Arimondo, E. (2002) Photoionization of ultracold and Bose-Einstein condensed Rb atoms. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/physics/0206019v1
10.1103/PhysRevA.66.043409
oai:eprints.adm.unipi.it:1360
2015-04-07T15:36:39Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1360/
Dynamical control of matter-wave tunneling in periodic potentials
Lignier, H.
Sias, C.
Ciampini, D.
Singh, Y.
Zenesini, A.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report on measurements of dynamical suppression of inter-well tunneling of
a Bose-Einstein condensate (BEC) in a strongly driven optical lattice. The
strong driving is a sinusoidal shaking of the lattice corresponding to a
time-varying linear potential, and the tunneling is measured by letting the BEC
freely expand in the lattice. The measured tunneling rate is reduced and, for
certain values of the shaking parameter, completely suppressed. Our results are
in excellent agreement with theoretical predictions. Furthermore, we have
verified that in general the strong shaking does not destroy the phase
coherence of the BEC, opening up the possibility of realizing quantum phase
transitions by using the shaking strength as the control parameter.
American Physical Society
2007-07-03
Article
PeerReviewed
Lignier, H. and Sias, C. and Ciampini, D. and Singh, Y. and Zenesini, A. and Morsch, O. and Arimondo, E. (2007) Dynamical control of matter-wave tunneling in periodic potentials. Physical review letters . ISSN 0031-9007
http://arxiv.org/abs/0707.0403v1
10.1103/PhysRevLett.99.220403
oai:eprints.adm.unipi.it:1362
2015-04-08T09:16:41Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1362/
Optimized loading of an optical dipole trap for the production of Chromium BECs
Bismut, G.
Pasquiou, B.
Ciampini, D.
Laburthe-Tolra, B.
Marechal, E.
Vernac, L.
Gorceix, O.
FIS/03 - Fisica della materia
We report on a strategy to maximize the number of chromium atoms transferred
from a magneto-optical trap into an optical trap through accumulation in
metastable states via strong optical pumping. We analyse how the number of
atoms in a chromium Bose Einstein condensate can be raised by a proper handling
of the metastable state populations. Four laser diodes have been implemented to
address the four levels that are populated during the MOT phase. The individual
importance of each state is specified. To stabilize two of our laser diode, we
have developed a simple ultrastable passive reference cavity whose long term
stability is better than 1 MHz.
Springer
2011-01-21
Article
PeerReviewed
Bismut, G. and Pasquiou, B. and Ciampini, D. and Laburthe-Tolra, B. and Marechal, E. and Vernac, L. and Gorceix, O. (2011) Optimized loading of an optical dipole trap for the production of Chromium BECs. Applied Physics B, 102 (1). pp. 1-9. ISSN 1432-0649
http://arxiv.org/abs/1004.3642v1
oai:eprints.adm.unipi.it:1364
2015-04-08T09:01:29Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D626F6F6B5F73656374696F6E
http://eprints.adm.unipi.it/1364/
Bose-Einstein condensates in 1D optical lattices: nonlinearity and Wannier-Stark spectra
Arimondo, Ennio
Ciampini, Donatella
Morsch, Oliver
FIS/03 - Fisica della materia
We present our experimental investigations on the subject of nonlinearity-modified Bloch-oscillations and of nonlinear Landau-Zener tunneling between two energy bands in a rubidium Bose Einstein condensate in an accelerated periodic potential. Nonlinearity introduces an asymmetry in
Landau-Zener tunneling. We also present measurements of resonantly enhanced tunneling between the Wannier-Stark energy levels for Bose-Einstein condensates
loaded into an optical lattice.
Springer
Denz, Cornelia
Flach, Sergej
Kivshar, Yuri
2007-08-03
Book Section
PeerReviewed
Arimondo, Ennio and Ciampini, Donatella and Morsch, Oliver (2007) Bose-Einstein condensates in 1D optical lattices: nonlinearity and Wannier-Stark spectra. In: Nonlinearities of Periodic Structures and Metamaterials. Springer, pp. 165-180. ISBN 978-3-642-02066-7
http://arxiv.org/abs/0708.0479v1
oai:eprints.adm.unipi.it:1365
2015-04-07T15:37:09Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1365/
Experimental investigation of tunneling times using Bose-Einstein
condensates
Ciampini, Donatella
Morsch, Oliver
Arimondo, Ennio
FIS/03 - Fisica della materia
The time it takes a quantum system to complete a tunneling event (which in
the case of cross-barrier tunneling can be viewed as the time spent in a
classically forbidden area) is related to the time required for a state to
evolve to an orthogonal state, and an observation, i.e., a quantum mechanical
projection on a particular basis, is required to distinguish one state from
another. We have performed time-resolved measurements of Landau-Zener tunneling
of Bose-Einstein condensates in accelerated optical lattices, clearly resolving
the steplike time dependence of the band populations. The use of different
protocols enabled us to access the tunneling probability, in two different
bases, namely, the adiabatic basis and the diabatic basis. The adiabatic basis
corresponds to the eigenstates of the lattice, and the diabatic one to the
freeparticle momentum eigenstates. Our findings pave the way towards more
quantitative studies of the tunneling time for LZ transitions, which are of
current interest in the context of optimal quantum control and the quantum
speed limit.
IOPScience
2011-02-08
Article
PeerReviewed
Ciampini, Donatella and Morsch, Oliver and Arimondo, Ennio (2011) Experimental investigation of tunneling times using Bose-Einstein condensates. Journal of physics: conference series . ISSN 1742-6596
http://arxiv.org/abs/1102.1666v1
oai:eprints.adm.unipi.it:1366
2015-04-07T15:30:08Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1366/
Quantum control in strongly driven optical lattices
Ciampini, Donatella
Morsch, Oliver
Arimondo, Ennio
FIS/03 - Fisica della materia
Matter waves can be coherently and adiabatically loaded and controlled in
strongly driven optical lattices. This coherent control is used in order to
modify the modulus and the sign of the tunneling matrix element in the
tunneling Hamiltonian. Our findings pave the way for studies of driven quantum
systems and new methods for engineering Hamiltonians that are impossible to
realize with static techniques.
World Scientific Publishing
2011-02-08
Article
PeerReviewed
Ciampini, Donatella and Morsch, Oliver and Arimondo, Ennio (2011) Quantum control in strongly driven optical lattices. International Journal of Quantum Information . ISSN 1793-6918
http://arxiv.org/pdf/1102.1670v1.pdf
oai:eprints.adm.unipi.it:1367
2015-04-07T15:38:33Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1367/
Observation of Stückelberg oscillations in accelerated optical
lattices
Zenesini, A.
Ciampini, D.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report the experimental observation of St\"{u}ckelberg oscillations of
matter waves in optical lattices. Extending previous work on Landau-Zener
tunneling of Bose-Einstein condensates in optical lattices, we study the
effects of the accumulated phase between two successive crossings of the
Brillouin zone edge. Our results agree well with a simple model for multiple
Landau-Zener tunneling events taking into account the band structure of the
optical lattice.
American Physical Society
2010-10-12
Article
PeerReviewed
Zenesini, A. and Ciampini, D. and Morsch, O. and Arimondo, E. (2010) Observation of Stückelberg oscillations in accelerated optical lattices. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/1010.2413v1
oai:eprints.adm.unipi.it:1372
2015-04-07T15:42:17Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1372/
Expansion of matter waves in static and driven periodic potentials
Creffield, C. E.
Sols, F.
Ciampini, D.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We study the non-equilibrium dynamics of cold atoms held in an optical
lattice potential. The expansion of an initially confined atom cloud occurs in
two phases: an initial quadratic expansion followed by a ballistic behaviour at
long times. Accounting for this gives a good description of recent experimental
results, and provides a robust method to extract the effective intersite
tunneling from time-of-flight measurements.
American Physical Society
2010
Article
PeerReviewed
Creffield, C. E. and Sols, F. and Ciampini, D. and Morsch, O. and Arimondo, E. (2010) Expansion of matter waves in static and driven periodic potentials. Physical review. A, Atomic, Molecular, and Optical Physics, 82 . 035601. ISSN 1094-1622
http://arxiv.org/abs/1008.0708v1
10.1103/PhysRevA.82.035601
oai:eprints.adm.unipi.it:1373
2015-04-07T15:38:03Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1373/
Rydberg tomography of an ultra-cold atomic cloud
Valado, M. M.
Malossi, N.
Scotto, S.
Ciampini, D.
Arimondo, E.
Morsch, O.
FIS/03 - Fisica della materia
One of the most striking features of the strong interactions between Rydberg
atoms is the dipole blockade effect, which allows only a single excitation to
the Rydberg state within the volume of the blockade sphere. Here we present a
method that spatially visualizes this phenomenon in an inhomogeneous gas of
ultra-cold rubidium atoms. In our experiment we scan the position of one of the
excitation lasers across the cold cloud and determine the number of Rydberg
excitations detected as a function of position. Comparing this distribution to
the one obtained for the number of ions created by a two-photon ionization
process via the intermediate 5P level, we demonstrate that the blockade effect
modifies the width of the Rydberg excitation profile. Furthermore, we study the
dynamics of the Rydberg excitation and find that the timescale for the
excitation depends on the atomic density at the beam position.
American Physical Society
2013-08-01
Article
PeerReviewed
Valado, M. M. and Malossi, N. and Scotto, S. and Ciampini, D. and Arimondo, E. and Morsch, O. (2013) Rydberg tomography of an ultra-cold atomic cloud. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/1308.0205v2
oai:eprints.adm.unipi.it:1374
2015-04-07T15:45:08Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1374/
Bose-Einstein condensation of rubidium atoms in a triaxial TOP-trap
Müller, J. H.
Ciampini, D.
Morsch, O.
Smirne, G.
Fazzi, M.
Verkerk, P.
Fuso, F.
Arimondo, E.
FIS/03 - Fisica della materia
We report the results of experiments with Bose-Einstein condensates of
rubidium atoms in a triaxial TOP-trap, presenting measurements of the
condensate fraction and the free expansion of a condensate released from the
trap. The experimental apparatus and the methods used to calibrate the magnetic
trapping fields are discussed in detail. Furthermore, we compare the
performance of our apparatus with other TOP-traps and discuss possible limiting
factors for the sizes of condensates achievable in such traps.
IOPScience
2000-05-08
Article
PeerReviewed
Müller, J. H. and Ciampini, D. and Morsch, O. and Smirne, G. and Fazzi, M. and Verkerk, P. and Fuso, F. and Arimondo, E. (2000) Bose-Einstein condensation of rubidium atoms in a triaxial TOP-trap. Journal of physics B, Atomic, molecular and optical physics, 33 (19). ISSN 1361-6455
http://arxiv.org/abs/cond-mat/0005133v1
10.1088/0953-4075/33/19/320
oai:eprints.adm.unipi.it:1375
2015-04-07T15:39:43Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1375/
Dynamics and phase evolution of Bose-Einstein condensates in
one-dimensional optical lattices
Morsch, O.
Cristiani, M.
Müller, J. H.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We report experimental results on the dynamics and phase evolution of
Bose-Einstein condensates in 1D optical lattices. The dynamical behaviour is
studied by adiabatically loading the condensate into the lattice and
subsequently switching off the magnetic trap. In this case, the condensate is
free to expand inside the periodic structure of the optical lattice. The phase
evolution of the condensate, on the other hand, can be studied by
non-adiabatically switching on the periodic potential. We observe decays and
revivals of the interference pattern after a time-of-flight.
American Physical Society
2002-09-02
Article
PeerReviewed
Morsch, O. and Cristiani, M. and Müller, J. H. and Ciampini, D. and Arimondo, E. (2002) Dynamics and phase evolution of Bose-Einstein condensates in one-dimensional optical lattices. Reviews of Modern Physics . ISSN 1539-0756
http://arxiv.org/abs/cond-mat/0209024v1
oai:eprints.adm.unipi.it:1376
2015-04-07T15:33:16Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1376/
Hitting a BEC with a comb: Evolution of interference patterns inside a
magnetic trap
Müller, J. H.
Morsch, O.
Cristiani, M.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We study the evolution inside a harmonic trap of Bose-Einstein condensates
released from the periodic potential of an optical lattice. After a
time-of-flight, harmonic motion of the interference peaks is observed as well
as a breathing motion in the direction perpendicular to the optical lattice. We
interpret these results in terms of a simple physical model and discuss the
possibility of more detailed studies of such a system.
IOP Publishing
2002-11-05
Article
PeerReviewed
Müller, J. H. and Morsch, O. and Cristiani, M. and Ciampini, D. and Arimondo, E. (2002) Hitting a BEC with a comb: Evolution of interference patterns inside a magnetic trap. Journal of Optics B: Quantum and Semiclassical Optics . ISSN 1464-4266
http://arxiv.org/abs/cond-mat/0211079v1
oai:eprints.adm.unipi.it:1377
2015-04-07T15:39:07Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1377/
Resonantly enhanced tunneling of Bose-Einstein condensates in periodic
potentials
Sias, C.
Zenesini, A.
Lignier, H.
Wimberger, S.
Ciampini, D.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report on measurements of resonantly enhanced tunneling of Bose-Einstein
condensates loaded into an optical lattice. By controlling the initial
conditions of our system we were able to observe resonant tunneling in the
ground and the first two excited states of the lattice wells. We also
investigated the effect of the intrinsic nonlinearity of the condensate on the
tunneling resonances.
American Physical Society
2007-02-23
Article
PeerReviewed
Sias, C. and Zenesini, A. and Lignier, H. and Wimberger, S. and Ciampini, D. and Morsch, O. and Arimondo, E. (2007) Resonantly enhanced tunneling of Bose-Einstein condensates in periodic potentials. Physical review letters . ISSN 0031-9007
http://arxiv.org/abs/cond-mat/0702552v1
oai:eprints.adm.unipi.it:1378
2015-04-07T15:44:28Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1378/
Photoionization of ultracold and Bose-Einstein condensed Rb atoms
Ciampini, D.
Anderlini, M.
Müller, J. H.
Fuso, F.
Morsch, O.
Thomsen, J. W.
Arimondo, E.
FIS/03 - Fisica della materia
Photoionization of a cold atomic sample offers intriguing possibilities to
observe collective effects at extremely low temperatures. Irradiation of a
rubidium condensate and of cold rubidium atoms within a magneto-optical trap
with laser pulses ionizing through 1-photon and 2-photon absorption processes
has been performed. Losses and modifications in the density profile of the
remaining trapped cold cloud or the remaining condensate sample have been
examined as function of the ionizing laser parameters. Ionization
cross-sections were measured for atoms in a MOT, while in magnetic traps losses
larger than those expected for ionization process were measured.
American Physical Society
2002-06-07
Article
PeerReviewed
Ciampini, D. and Anderlini, M. and Müller, J. H. and Fuso, F. and Morsch, O. and Thomsen, J. W. and Arimondo, E. (2002) Photoionization of ultracold and Bose-Einstein condensed Rb atoms. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/physics/0206019v1
10.1103/PhysRevA.66.043409
oai:eprints.adm.unipi.it:1379
2015-04-03T10:25:38Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1379/
Manipulation of ultracold atomic mixtures using microwave techniques
Ciampini, D.
Courtade, E.
Sias, C.
Cossart, D.
Carelli, G.
Mango, F.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We used microwave radiation to evaporatively cool a mixture of of 133Cs and
87Rb atoms in a magnetic trap. A mixture composed of an equal number (around
10^4) of Rb and Cs atoms in their doubly polarized states at ultracold
temperatures was prepared. We also used microwaves to selectively evaporate
atoms in different Zeeman states.
Elsevier
2004-11-10
Article
PeerReviewed
Ciampini, D. and Courtade, E. and Sias, C. and Cossart, D. and Carelli, G. and Mango, F. and Morsch, O. and Arimondo, E. (2004) Manipulation of ultracold atomic mixtures using microwave techniques. Optics Communications . ISSN 0030-4018
http://www.sciencedirect.com/science/article/pii/S0030401805007418
oai:eprints.adm.unipi.it:1380
2015-04-07T15:43:25Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1380/
Dynamical control of matter-wave tunneling in periodic potentials
Lignier, H.
Sias, C.
Ciampini, D.
Singh, Y.
Zenesini, A.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report on measurements of dynamical suppression of inter-well tunneling of
a Bose-Einstein condensate (BEC) in a strongly driven optical lattice. The
strong driving is a sinusoidal shaking of the lattice corresponding to a
time-varying linear potential, and the tunneling is measured by letting the BEC
freely expand in the lattice. The measured tunneling rate is reduced and, for
certain values of the shaking parameter, completely suppressed. Our results are
in excellent agreement with theoretical predictions. Furthermore, we have
verified that in general the strong shaking does not destroy the phase
coherence of the BEC, opening up the possibility of realizing quantum phase
transitions by using the shaking strength as the control parameter.
American Physical Society
2007-07-03
Article
PeerReviewed
Lignier, H. and Sias, C. and Ciampini, D. and Singh, Y. and Zenesini, A. and Morsch, O. and Arimondo, E. (2007) Dynamical control of matter-wave tunneling in periodic potentials. Physical review letters . ISSN 0031-9007
http://arxiv.org/abs/0707.0403v1
10.1103/PhysRevLett.99.220403
oai:eprints.adm.unipi.it:1381
2015-04-08T08:28:57Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1381/
Tunneling control and localization for Bose-Einstein condensates in a
frequency modulated optical lattice
Zenesini, A.
Lignier, H.
Sias, C.
Morsch, O.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
The similarity between matter waves in periodic potential and solid-state
physics processes has triggered the interest in quantum simulation using
Bose-Fermi ultracold gases in optical lattices. The present work evidences the
similarity between electrons moving under the application of oscillating
electromagnetic fields and matter waves experiencing an optical lattice
modulated by a frequency difference, equivalent to a spatially shaken periodic
potential. We demonstrate that the tunneling properties of a Bose-Einstein
condensate in shaken periodic potentials can be precisely controlled. We take
additional crucial steps towards future applications of this method by proving
that the strong shaking of the optical lattice preserves the coherence of the
matter wavefunction and that the shaking parameters can be changed
adiabatically, even in the presence of interactions. We induce reversibly the
quantum phase transition to the Mott insulator in a driven periodic potential.
IOP Publishing
2009-12-07
Article
PeerReviewed
Zenesini, A. and Lignier, H. and Sias, C. and Morsch, O. and Ciampini, D. and Arimondo, E. (2009) Tunneling control and localization for Bose-Einstein condensates in a frequency modulated optical lattice. Laser Physics . ISSN 1555-6611
http://arxiv.org/abs/0912.1241v1
oai:eprints.adm.unipi.it:1384
2015-04-07T15:54:59Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1384/
Coherent control of dressed matter waves
Zenesini, Alessandro
Lignier, Hans
Ciampini, Donatella
Morsch, Oliver
Arimondo, Ennio
FIS/03 - Fisica della materia
By moving the pivot of a pendulum rapidly up and down one can create a stable
position with the pendulum's bob above the pivot rather than below it. This
surprising and counterintuitive phenomenon is a widespread feature of driven
systems and carries over into the quantum world. Even when the static
properties of a quantum system are known, its response to an explicitly
time-dependent variation of its parameters may be highly nontrivial, and
qualitatively new states can appear that were absent in the original system. In
quantum mechanics the archetype for this kind of behaviour is an atom in a
radiation field, which exhibits a number of fundamental phenomena such as the
modification of its g-factor in a radio-frequency field and the dipole force
acting on an atom moving in a spatially varying light field. These effects can
be successfully described in the so-called dressed atom picture. Here we show
that the concept of dressing can also be applied to macroscopic matter waves,
and that the quantum states of "dressed matter waves" can be coherently
controlled. In our experiments we use Bose-Einstein condensates in driven
optical lattices and demonstrate that the many-body state of this system can be
adiabatically and reversibly changed between a superfluid and a Mott insulating
state by varying the amplitude of the driving. Our setup represents a versatile
testing ground for driven quantum systems, and our results indicate the
direction towards new quantum control schemes for matter waves.
American Physical Society
2008-09-04
Article
PeerReviewed
Zenesini, Alessandro and Lignier, Hans and Ciampini, Donatella and Morsch, Oliver and Arimondo, Ennio (2008) Coherent control of dressed matter waves. Physical review letters . ISSN 0031-9007
http://arxiv.org/abs/0809.0768v1
10.1103/PhysRevLett.102.100403
oai:eprints.adm.unipi.it:1386
2015-04-08T08:21:49Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D626F6F6B5F73656374696F6E
http://eprints.adm.unipi.it/1386/
Kilohertz-driven Bose-Einstein condensates in optical lattices
Arimondo, Ennio
Ciampini, Donatella
Eckardt, André
Holthaus, Martin
Morsch, Oliver
FIS/03 - Fisica della materia
We analyze time-of-flight absorption images obtained with dilute
Bose-Einstein con-densates released from shaken optical lattices, both
theoretically and experimentally. We argue that weakly interacting, ultracold
quantum gases in kilohertz-driven optical potentials constitute equilibrium
systems characterized by a steady-state distri-bution of Floquet-state
occupation numbers. Our experimental results consistently indicate that a
driven ultracold Bose gas tends to occupy a single Floquet state, just as it
occupies a single energy eigenstate when there is no forcing. When the driving
amplitude is sufficiently high, the Floquet state possessing the lowest mean
energy does not necessarily coincide with the Floquet state connected to the
ground state of the undriven system. We observe strongly driven Bose gases to
condense into the former state under such conditions, thus providing nontrivial
examples of dressed matter waves.
Elsevier
2012
Book Section
PeerReviewed
Arimondo, Ennio and Ciampini, Donatella and Eckardt, André and Holthaus, Martin and Morsch, Oliver (2012) Kilohertz-driven Bose-Einstein condensates in optical lattices. In: Advances In Atomic, Molecular, and Optical Physics. Elsevier, p. 515.
http://arxiv.org/abs/1203.1259v2
10.1016/B978-0-12-396482-3.00010-7
oai:eprints.adm.unipi.it:1387
2015-04-07T15:40:17Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1387/
Rydberg excitation of a Bose-Einstein condensate
Viteau, M.
Bason, M.
Radogostowicz, J.
Malossi, N.
Morsch, O.
Ciampini, D.
Arimondo, E.
FIS/03 - Fisica della materia
We have performed two-photon excitation via the 6P3/2 state to n=50-80 S or D
Rydberg state in Bose-Einstein condensates of rubidium atoms. The Rydberg
excitation was performed in a quartz cell, where electric fields generated by
plates external to the cell created electric charges on the cell walls.
Avoiding accumulation of the charges and realizing good control over the
applied electric field was obtained when the fields were applied only for a
short time, typically a few microseconds. Rydberg excitations of the
Bose-Einstein condensates loaded into quasi one-dimensional traps and in
optical lattices have been investigated. The results for condensates expanded
to different sizes in the one-dimensional trap agree well with the intuitive
picture of a chain of Rydberg excitations controlled by the dipole-dipole
interaction. The optical lattice applied along the one-dimensional geometry
produces localized, collective Rydberg excitations controlled by the
nearest-neighbour blockade.
IOP Publishing
2012-03-06
Article
PeerReviewed
Viteau, M. and Bason, M. and Radogostowicz, J. and Malossi, N. and Morsch, O. and Ciampini, D. and Arimondo, E. (2012) Rydberg excitation of a Bose-Einstein condensate. Laser Physics . ISSN 1555-6611
http://arxiv.org/abs/1203.1261v1
oai:eprints.adm.unipi.it:1389
2015-04-07T15:45:47Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1389/
Unearthing wave-function renormalization effects in the time evolution
of a Bose-Einstein condensate
Facchi, Paolo
Pascazio, Saverio
Pepe, Francesco V.
Arimondo, Ennio
Ciampini, Donatella
Morsch, Oliver
FIS/03 - Fisica della materia
We study the time evolution of a Bose-Einstein condensate in an accelerated
optical lattice. When the condensate has a narrow quasimomentum distribution
and the optical lattice is shallow, the survival probability in the ground band
exhibits a steplike structure. In this regime we establish a connection between
the wave-function renormalization parameter $Z$ and the phenomenon of
resonantly enhanced tunneling.
American Physical Society
2013
Article
PeerReviewed
Facchi, Paolo and Pascazio, Saverio and Pepe, Francesco V. and Arimondo, Ennio and Ciampini, Donatella and Morsch, Oliver (2013) Unearthing wave-function renormalization effects in the time evolution of a Bose-Einstein condensate. Physica Scripta, T153 . 014024. ISSN 1402-4896
http://arxiv.org/abs/1211.1822v1
10.1088/0031-8949/2013/T153/014024
oai:eprints.adm.unipi.it:1390
2015-04-08T08:18:59Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1390/
Excitation and damping of collective modes of a Bose-Einstein condensate in a one-dimensional lattice
Morsch, O.
Müller, J. H.
Ciampini, D.
Cristiani, M.
Blakie, P. B.
Williams, C. J.
Julienne, P. S.
Arimondo, E.
FIS/03 - Fisica della materia
The mode structure of a Bose-Einstein condensate non-adiabatically loaded
into a one-dimensional optical lattice is studied by analyzing the visibility
of the interference pattern as well as the radial profile of the condensate
after a time-of-flight. A simple model is proposed that predicts the short-time
decrease of the visibility as a function of the condensate parameters. In the
radial direction, heavily damped oscillations are observed, as well as an
increase in the condensate temperature. These findings are interpreted as a
re-thermalization due to dissipation of the initial condensate excitations into
high-lying modes.
American Physical Society
2002-08-08
Article
PeerReviewed
Morsch, O. and Müller, J. H. and Ciampini, D. and Cristiani, M. and Blakie, P. B. and Williams, C. J. and Julienne, P. S. and Arimondo, E. (2002) Excitation and damping of collective modes of a Bose-Einstein condensate in a one-dimensional lattice. Physical review. A, Atomic, Molecular, and Optical Physics, 67 . ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0208162v1
10.1103/PhysRevA.67.031603
oai:eprints.adm.unipi.it:1391
2015-04-08T09:18:42Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1391/
Sympathetic cooling and collisional properties of a Rb-Cs mixture
Anderlini, M.
Courtade, E.
Cristiani, M.
Cossart, D.
Ciampini, D.
Sias, C.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We report on measurements of the collisional properties of a mixture of
$^{133}$Cs and $^{87}$Rb atoms in a magnetic trap at $\mu\mathrm{K}$
temperatures. By selectively evaporating the Rb atoms using a radio-frequency
field, we achieved sympathetic cooling of Cs down to a few $\mu\mathrm{K}$. The
inter-species collisional cross-section was determined through rethermalization
measurements, leading to an estimate of $a_s=595 a_0$ for the s-wave scattering
length for Rb in the $|F=2, m_F=2>$ and Cs in the $|F=4, m_F=4>$ magnetic
states. We briefly speculate on the prospects for reaching Bose-Einstein
condensation of Cs inside a magnetic trap through sympathetic cooling.
American Physical Society
2004-10-22
Article
PeerReviewed
Anderlini, M. and Courtade, E. and Cristiani, M. and Cossart, D. and Ciampini, D. and Sias, C. and Morsch, O. and Arimondo, E. (2004) Sympathetic cooling and collisional properties of a Rb-Cs mixture. Physical review. A, Atomic, Molecular, and Optical Physics . ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0410565v2
10.1103/PhysRevA.71.061401
oai:eprints.adm.unipi.it:1392
2015-04-03T07:25:59Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1392/
Observation of photon-assisted tunneling in optical lattices
Sias, C.
Lignier, H.
Singh, Y. P.
Zenesini, A.
Ciampini, D.
Morsch, O.
Arimondo, E.
FIS/03 - Fisica della materia
We have observed tunneling suppression and photon-assisted tunneling of
Bose-Einstein condensates in an optical lattice subjected to a constant force
plus a sinusoidal shaking. For a sufficiently large constant force, the ground
energy levels of the lattice are shifted out of resonance and tunneling is
suppressed; when the shaking is switched on, the levels are coupled by
low-frequency photons and tunneling resumes. Our results agree well with
theoretical predictions and demonstrate the usefulness of optical lattices for
studying solid-state phenomena.
American Physical Society
2007-09-20
Article
PeerReviewed
Sias, C. and Lignier, H. and Singh, Y. P. and Zenesini, A. and Ciampini, D. and Morsch, O. and Arimondo, E. (2007) Observation of photon-assisted tunneling in optical lattices. Physical review letters . ISSN 0031-9007
http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.100.040404
10.1103/PhysRevLett.100.040404
oai:eprints.adm.unipi.it:1394
2014-02-12T16:51:53Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3032
74797065733D61727469636C65
http://eprints.adm.unipi.it/1394/
Trap modulation spectroscopy of the Mott-insulator transition in optical lattices
Lignier, H.
Zenesini, A.
Ciampini, D.
Morsch, O.
Arimondo, E.
Montangero, S.
Pupillo, G.
Fazio, R.
FIS/02 - Fisica teorica, modelli e metodi matematici
We introduce a new technique to probe the properties of an interacting cold
atomic gas that can be viewed as a dynamical compressibility measurement. We
apply this technique to the study of the superfluid to Mott insulator quantum
phase transition in one and three dimensions for a bosonic gas trapped in an
optical lattice. Excitations of the system are detected by time-of-flight
measurements. The experimental data for the one-dimensional case are in good
agreement with the results of a time-dependent density matrix renormalization
group calculation.
American Physical Society
2008-12-16
Article
PeerReviewed
Lignier, H. and Zenesini, A. and Ciampini, D. and Morsch, O. and Arimondo, E. and Montangero, S. and Pupillo, G. and Fazio, R. (2008) Trap modulation spectroscopy of the Mott-insulator transition in optical lattices. Physical review. A, Atomic, Molecular, and Optical Physics, 79 (4). 041601. ISSN 1094-1622
http://arxiv.org/abs/0812.3005v1
10.1103/PhysRevA.79.041601
oai:eprints.adm.unipi.it:1399
2014-01-29T22:44:58Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1399/
Cooperative excitation and many-body interactions in a cold Rydberg gas
Viteau, Matthieu
Huillery, Paul
Bason, Mark G.
Malossi, Nicola
Ciampini, Donatella
Morsch, Oliver
Arimondo, Ennio
Comparat, Daniel
Pillet, Pierre
FIS/03 - Fisica della materia
The dipole blockade of Rydberg excitations is a hallmark of the strong
interactions between atoms in these high-lying quantum states. One of the
consequences of the dipole blockade is the suppression of fluctuations in the
counting statistics of Rydberg excitations, of which some evidence has been
found in previous experiments. Here we present experimental results on the
dynamics and the counting statistics of Rydberg excitations of ultra-cold
Rubidium atoms both on and off resonance, which exhibit sub- and
super-Poissonian counting statistics, respectively. We compare our results with
numerical simulations using a novel theoretical model based on Dicke states of
Rydberg atoms including dipole-dipole interactions, finding good agreement
between experiment and theory.
2012-06-22
Article
NonPeerReviewed
Viteau, Matthieu and Huillery, Paul and Bason, Mark G. and Malossi, Nicola and Ciampini, Donatella and Morsch, Oliver and Arimondo, Ennio and Comparat, Daniel and Pillet, Pierre (2012) Cooperative excitation and many-body interactions in a cold Rydberg gas. arXiv .
http://arxiv.org/abs/1206.5086v1
oai:eprints.adm.unipi.it:1418
2013-09-10T15:06:49Z
oai:eprints.adm.unipi.it:1419
2013-09-10T14:43:12Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1419/
Quasi symplectic integrators for stochastic differential equations
Mannella, Riccardo
FIS/03 - Fisica della materia
SUMMARY Two specialized algorithms for the numerical integration of the equations of
motion of a Brownian walker obeying detailed balance are introduced. The
algorithms become symplectic in the appropriate limits, and reproduce the
equilibrium distributions to some higher order in the integration time step.
Comparisons with other existing integration schemes are carried out both for
static and dynamical quantities.
American Physical Society
2003-12-04
Article
PeerReviewed
Mannella, Riccardo (2003) Quasi symplectic integrators for stochastic differential equations. Physical review. E, Statistical, nonlinear, and soft matter physics, 69 (4). 041107 . ISSN 1550-2376
http://arxiv.org/abs/cond-mat/0312109v1
10.1103/PhysRevE.69.041107
oai:eprints.adm.unipi.it:1420
2013-09-10T15:19:16Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1420/
A Dynamical Approach to Fractional Brownian Motion
Mannella, Riccardo
Grigolini, P
West, BJ
FIS/03 - Fisica della materia
SUMMARY Herein we develop a dynamical foundation for fractional Brownian Motion. A
clear relation is established between the asymptotic behaviour of the
correlation function and diffusion in a dynamical system. Then, assuming that
scaling is applicable, we establish a connection between diffusion (either
standard or anomalous) and the dynamical indicator known as the Hurst
coefficient. We argue on the basis of numerical simulations that although we
have been able to prove scaling only for "Gaussian" processes, our conclusions
may well apply to a wider class of systems. On the other hand systems exist for
which scaling might not hold, so we speculate on the possible consequence on
the various relations derived in the paper on such systems.
1993-08-09
Article
NonPeerReviewed
Mannella, Riccardo and Grigolini, P and West, BJ (1993) A Dynamical Approach to Fractional Brownian Motion. arXiv .
http://arxiv.org/abs/chao-dyn/9308004v1
oai:eprints.adm.unipi.it:1421
2013-08-06T10:57:48Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1421/
Numerical integration of stochastic differential equations
Mannella, Riccardo
FIS/03 - Fisica della materia
SUMMARY Numerical algorithms for the integration of stochastic differential equations
in the presence of white noise are introduced and compared. Algorithms for the
integration of stochastic correlated forces are also briefly reviewed. Finally,
a specialised algorithm for two dimensional systems is derived, having in mind
the integration of particles in the liquid state.
1997-09-29
Article
NonPeerReviewed
Mannella, Riccardo (1997) Numerical integration of stochastic differential equations. arXiv .
oai:eprints.adm.unipi.it:1425
2013-08-06T11:50:17Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1425/
Oscillation Frequencies for a Bose Condensate in a Triaxial Magnetic Trap
Cerboneschi, E.
Mannella, R.
Arimondo, E.
Salasnich, L.
FIS/03 - Fisica della materia
SUMMARY We investigate the dynamics of a Bose condensate, interacting with either
repulsive or attractive forces, confined in a fully anisotropic harmonic
potential. The (3+1)-dimensional Gross-Pitaevskii equation is integrated
numerically to derive the collective excitation frequencies, showing a good
agreement with those calculated with a variational technique.
Elsevier Science
1998-09-28
Article
PeerReviewed
Cerboneschi, E. and Mannella, R. and Arimondo, E. and Salasnich, L. (1998) Oscillation Frequencies for a Bose Condensate in a Triaxial Magnetic Trap. Physics Letters A, 249 (5-6). pp. 495-500. ISSN 1873-2429
http://arxiv.org/abs/cond-mat/9809371v1
10.1016/S0375-9601(98)00732-4
oai:eprints.adm.unipi.it:1426
2013-08-06T11:51:56Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1426/
Macroscopic Manifestation of Microscopic Entropy Production: Space-Dependent Intermittence
Grigolini, Paolo
Mannella, Riccardo
Palatella, Luigi
FIS/03 - Fisica della materia
SUMMARY We study a spatial diffusion process generated by velocity fluctuations of
intermittent nature. We note that intermittence reduces the entropy production
rate while enhancing the diffusion strength. We study a case of space-dependent
intermittence and prove it to result in a deviation from uniform distribution.
This macroscopic effect can be used to measure the relative value of the
trajectory entropy.
2000-11-29
Article
NonPeerReviewed
Grigolini, Paolo and Mannella, Riccardo and Palatella, Luigi (2000) Macroscopic Manifestation of Microscopic Entropy Production: Space-Dependent Intermittence. arXiv .
http://arxiv.org/abs/cond-mat/0011493v1
oai:eprints.adm.unipi.it:1427
2013-08-06T11:47:23Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1427/
Tunnelling rates for the nonlinear Wannier-Stark problem
Wimberger, Sandro
Schlagheck, Peter
Mannella, Riccardo
FIS/03 - Fisica della materia
SUMMARY We present a method to numerically compute accurate tunnelling rates for a
Bose-Einstein condensate which is described by the nonlinear Gross-Pitaevskii
equation. Our method is based on a sophisticated real-time integration of the
complex-scaled Gross-Pitaevskii equation, and it is capable of finding the
stationary eigenvalues for the Wannier-Stark problem. We show that even weak
nonlinearities have significant effects in the vicinity of very sensitive
resonant tunnelling peaks, which occur in the rates as a function of the Stark
field amplitude. The mean-field interaction induces a broadening and a shift of
the peaks, and the latter is explained by analytic perturbation theory.
IOPScience
2006
Article
PeerReviewed
Wimberger, Sandro and Schlagheck, Peter and Mannella, Riccardo (2006) Tunnelling rates for the nonlinear Wannier-Stark problem. Journal of physics B, Atomic, molecular and optical physics, 39 . p. 729. ISSN 1361-6455
http://arxiv.org/abs/cond-mat/0512481v1
10.1088/0953-4075/39/3/024
oai:eprints.adm.unipi.it:1428
2013-08-06T11:36:19Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1428/
Drastic facilitation of the onset of global chaos in a periodically driven Hamiltonian system due to an extremum in the dependence of eigenfrequency on energy
Soskin, S. M.
Yevtushenko, O. M.
Mannella, R.
FIS/03 - Fisica della materia
SUMMARY The Chirikov resonance-overlap criterion predicts the onset of global chaos
if nonlinear resonances overlap in energy, which is conventionally assumed to
require a non-small magnitude of perturbation. We show that, for a
time-periodic perturbation, the onset of global chaos may occur at unusually
{\it small} magnitudes of perturbation if the unperturbed system possesses more
than one separatrix. The relevant scenario is the combination of the overlap in
the phase space between resonances of the same order and their overlap in
energy with chaotic layers associated with separatrices of the unperturbed
system. One of the most important manifestations of this effect is a drastic
increase of the energy range involved into the unbounded chaotic transport in
spatially periodic system driven by a rather {\it weak} time-periodic force,
provided the driving frequency approaches the extremal eigenfrequency or its
harmonics. We develop the asymptotic theory and verify it in simulations.
American Physical Society
2003
Article
PeerReviewed
Soskin, S. M. and Yevtushenko, O. M. and Mannella, R. (2003) Drastic facilitation of the onset of global chaos in a periodically driven Hamiltonian system due to an extremum in the dependence of eigenfrequency on energy. Physical review letters, 90 . p. 174101. ISSN 0031-9007
http://arxiv.org/abs/nlin/0206002v4
10.1103/PhysRevLett.90.174101
oai:eprints.adm.unipi.it:1429
2013-08-06T11:38:10Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1429/
Divergence of the Chaotic Layer Width and Strong Acceleration of the Spatial Chaotic Transport in Periodic Systems Driven by an Adiabatic ac Force
Soskin, S. M.
Yevtushenko, O. M.
Mannella, R.
FIS/03 - Fisica della materia
SUMMARY We show for the first time that a {\it weak} perturbation in a Hamiltonian
system may lead to an arbitrarily {\it wide} chaotic layer and {\it fast}
chaotic transport. This {\it generic} effect occurs in any spatially periodic
Hamiltonian system subject to a sufficiently slow ac force. We explain it and
develop an explicit theory for the layer width, verified in simulations.
Chaotic spatial transport as well as applications to the diffusion of particles
on surfaces, threshold devices and others are discussed.
American Physical Society
2005
Article
PeerReviewed
Soskin, S. M. and Yevtushenko, O. M. and Mannella, R. (2005) Divergence of the Chaotic Layer Width and Strong Acceleration of the Spatial Chaotic Transport in Periodic Systems Driven by an Adiabatic ac Force. Physical review letters, 95 . p. 224101. ISSN 0031-9007
http://arxiv.org/abs/nlin/0408022v2
10.1103/PhysRevLett.95.224101
oai:eprints.adm.unipi.it:1430
2013-08-06T11:28:32Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1430/
Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?
Tomadin, Andrea
Mannella, Riccardo
Wimberger, Sandro
FIS/03 - Fisica della materia
SUMMARY We investigate the parametric fluctuations in the quantum survival
probability of an open version of the delta-kicked rotor model in the deep
quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E
vol. 65 015203(R)] predict the existence of parametric fractal fluctuations
owing to the strong dynamical localisation of the eigenstates of the kicked
rotor. We discuss the possibility of observing such dynamically-induced
fractality in the quantum survival probability as a function of the kicking
period for the atom-optics realisation of the kicked rotor. The influence of
the atoms' initial momentum distribution is studied as well as the dependence
of the expected fractal dimension on finite-size effects of the experiment,
such as finite detection windows and short measurement times. Our results show
that clear signatures of fractality could be observed in experiments with cold
atoms subjected to periodically flashed optical lattices, which offer an
excellent control on interaction times and the initial atomic ensemble.
IOPScience
2006
Article
PeerReviewed
Tomadin, Andrea and Mannella, Riccardo and Wimberger, Sandro (2006) Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment? Journal of Physics A: Mathematical and General, 39 (10). p. 2477. ISSN 1361-6447
http://arxiv.org/abs/nlin/0512002v1
10.1088/0305-4470/39/10/015
oai:eprints.adm.unipi.it:1431
2013-08-06T11:36:12Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1431/
New approach to the treatment of separatrix chaos and its application to the global chaos onset between adjacent separatrices
Soskin, S. M.
Mannella, R.
Yevtushenko, O. M.
FIS/03 - Fisica della materia
SUMMARY We have developed the {\it general method} for the description of {\it
separatrix chaos}, basing on the analysis of the separatrix map dynamics.
Matching it with the resonant Hamiltonian analysis, we show that, for a given
amplitude of perturbation, the maximum width of the chaotic layer in energy may
be much larger than it was assumed before. We apply the above theory to explain
the drastic facilitation of global chaos onset in time-periodically perturbed
Hamiltonian systems possessing two or more separatrices, previously discovered
(PRL 90, 174101 (2003)). The theory well agrees with simulations. We also
discuss generalizations and applications. Examples of applications of the
facilitation include: the increase of the DC conductivity in spatially periodic
structures, the reduction of activation barriers for noise-induced transitions
and the related acceleration of spatial diffusion, the facilitation of the
stochastic web formation in a wave-driven or kicked oscillator.
2006-12-13
Article
NonPeerReviewed
Soskin, S. M. and Mannella, R. and Yevtushenko, O. M. (2006) New approach to the treatment of separatrix chaos and its application to the global chaos onset between adjacent separatrices. arXiv .
http://arxiv.org/abs/nlin/0612034v2
oai:eprints.adm.unipi.it:1437
2013-09-10T14:49:31Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1437/
Comment on "Influence of Noise on Force Measurement" [arXiv:1004.0874]
Mannella, Riccardo
McClintock, P. V. E.
FIS/03 - Fisica della materia
SUMMARY In a recent Letter [arXiv:1004.0874], Volpe et al. describe experiments on a
colloidal particle near a wall in the presence of a gravitational field for
which they study the influence of noise on the measurement of force. Their
central result is a striking discrepancy between the forces derived from
experimental drift measurements via their Eq. (1), and from the equilibrium
distribution. From this discrepancy they infer the stochastic calculus realised
in the system.
We comment, however: (a) that Eq. (1) does not hold for space-dependent
diffusion, and corrections should be introduced; and (b) that the "force"
derived from the drift need not coincide with the "force" obtained from the
equilibrium distribution.
2010-12-24
Article
NonPeerReviewed
Mannella, Riccardo and McClintock, P. V. E. (2010) Comment on "Influence of Noise on Force Measurement" [arXiv:1004.0874]. arXiv .
http://arxiv.org/abs/1012.5371v1
oai:eprints.adm.unipi.it:1440
2013-08-06T11:20:42Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1440/
Noise delayed decay of unstable states: theory versus numerical simulations
Agudov, N. V.
Mannella, R.
Safonov, A. V.
Spagnolo, B.
FIS/03 - Fisica della materia
SUMMARY We study the noise delayed decay of unstable nonequilibrium states in
nonlinear dynamical systems within the framework of the overdamped Brownian
motion model. We give the exact expressions for the decay times of unstable
states for polynomial potential profiles and obtain nonmonotonic behavior of
the decay times as a function of the noise intensity for the unstable
nonequilibrium states. The analytical results are compared with numerical
simulations.
IOPScience
2004-05-18
Article
PeerReviewed
Agudov, N. V. and Mannella, R. and Safonov, A. V. and Spagnolo, B. (2004) Noise delayed decay of unstable states: theory versus numerical simulations. Journal of Physics A: Mathematical and General, 37 (20). 5279 -5287. ISSN 1361-6447
http://arxiv.org/abs/cond-mat/0405394v2
10.1088/0305-4470/37/20/001
oai:eprints.adm.unipi.it:1441
2013-08-06T11:24:03Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1441/
Resonant nonlinear quantum transport for a periodically kicked Bose condensate
Wimberger, Sandro
Mannella, Riccardo
Morsch, Oliver
Arimondo, Ennio
FIS/03 - Fisica della materia
SUMMARY Our realistic numerical results show that the fundamental and higher-order
quantum resonances of the delta-kicked rotor are observable in state-of-the-art
experiments with a Bose condensate in a shallow harmonic trap, kicked by a
spatially periodic optical lattice. For stronger confinement,
interaction-induced destruction of the resonant motion of the kicked harmonic
oscillator is predicted.
American Physical Society
2005
Article
PeerReviewed
Wimberger, Sandro and Mannella, Riccardo and Morsch, Oliver and Arimondo, Ennio (2005) Resonant nonlinear quantum transport for a periodically kicked Bose condensate. Physical review letters, 94 . p. 130404. ISSN 0031-9007
http://arxiv.org/abs/cond-mat/0501565v2
10.1103/PhysRevLett.94.130404
oai:eprints.adm.unipi.it:1442
2013-08-06T11:02:47Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1442/
Atomic micromotion and geometric forces in a triaxial magnetic trap
Müller, J. H.
Morsch, O.
Ciampini, D.
Anderlini, M.
Mannella, R.
Arimondo, E.
FIS/03 - Fisica della materia
SUMMARY Non-adiabatic motion of Bose-Einstein condensates of rubidium atoms arising
from the dynamical nature of a time-orbiting-potential (TOP) trap was observed
experimentally. The orbital micromotion of the condensate in velocity space at
the frequency of the rotating bias field of the TOP was detected by a
time-of-flight method. A dependence of the equilibrium position of the atoms on
the sense of rotation of the bias field was observed. We have compared our
experimental findings with numerical simulations. The nonadiabatic following of
the atomic spin in the trap rotating magnetic field produces geometric forces
acting on the trapped atoms.
American Physical Society
2000-05-30
Article
PeerReviewed
Müller, J. H. and Morsch, O. and Ciampini, D. and Anderlini, M. and Mannella, R. and Arimondo, E. (2000) Atomic micromotion and geometric forces in a triaxial magnetic trap. Physical review letters, 85 . pp. 4454-4457. ISSN 0031-9007
http://arxiv.org/abs/physics/0005081v1
10.1103/PhysRevLett.85.4454
oai:eprints.adm.unipi.it:1443
2013-09-10T15:28:50Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1443/
Supernarrow Spectral Peaks and High Frequency Stochastic Resonance in Systems with Coexisting Periodic Attractors
Dykman, MI
Luchinsky, DG
Mannella, Riccardo
McClintock, PVE
Stein, ND
Stocks, NG
FIS/03 - Fisica della materia
SUMMARY The kinetics of a periodically driven nonlinear oscillator, bistable in a
nearly resonant field, has been investigated theoretically and through analogue
experiments. An activation dependence of the probabilities of fluctuational
transitions between the coexisting attractors has been observed, and the
activation energies of the transitions have been calculated and measured for a
wide range of parameters. The position of the kinetic phase transition (KPT),
at which the populations of the attractors are equal, has been established. A
range of critical phenomena is shown to arise in the vicinity of the KPT
including, in particular, the appearance of a supernarrow peak in the spectral
density of the fluctuations, and the occurrence of high-frequency stochastic
resonance (HFSR). The experimental measurements of the transition
probabilities, the KPT line, the multipeaked spectral densities, the strength
of the supernarrow spectral peak, and of the HFSR effect are shown to be in
good agreement with the theoretical predictions.
American Physical Society
1993-08-09
Article
PeerReviewed
Dykman, MI and Luchinsky, DG and Mannella, Riccardo and McClintock, PVE and Stein, ND and Stocks, NG (1993) Supernarrow Spectral Peaks and High Frequency Stochastic Resonance in Systems with Coexisting Periodic Attractors. Physical review. E, Statistical, nonlinear, and soft matter physics, 49 . pp. 1198-1215. ISSN 1550-2376
http://arxiv.org/abs/chao-dyn/9308003v1
10.1103/PhysRevE.49.1198
oai:eprints.adm.unipi.it:1444
2013-08-06T11:07:08Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1444/
A ratchet driven by quasimonochromatic noise
Arrayas, M.
Mannella, R.
McClintock, P. V. E.
McKane, A. J.
Stein, N. D.
FIS/03 - Fisica della materia
SUMMARY The currents generated by noise-induced activation processes in a periodic
potential are investigated analytically, by digital simulation and by
performing analogue experiments.
American Physical Society
1999-08-24
Article
PeerReviewed
Arrayas, M. and Mannella, R. and McClintock, P. V. E. and McKane, A. J. and Stein, N. D. (1999) A ratchet driven by quasimonochromatic noise. Physical review. E, Statistical, nonlinear, and soft matter physics, 61 . pp. 139-146. ISSN 1550-2376
http://arxiv.org/abs/cond-mat/9908342v1
10.1103/PhysRevE.61.139
oai:eprints.adm.unipi.it:1445
2013-08-06T11:12:12Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1445/
Nonlinearity induced destruction of resonant tunneling in the
Wannier-Stark problem
Wimberger, Sandro
Mannella, Riccardo
Morsch, Oliver
Arimondo, Ennio
Kolovsky, Andrey
Buchleitner, Andreas
FIS/03 - Fisica della materia
SUMMARY We present detailed numerical results on the dynamics of a Bose-Einstein
condensate in a tilted periodic optical lattice over many Bloch periods. We
show that an increasing atom-atom interaction systematically affects coherent
tunneling, and eventually destroys the resonant tunneling peaks.
American Physical Society
2005
Article
PeerReviewed
Wimberger, Sandro and Mannella, Riccardo and Morsch, Oliver and Arimondo, Ennio and Kolovsky, Andrey and Buchleitner, Andreas (2005) Nonlinearity induced destruction of resonant tunneling in the Wannier-Stark problem. Physical review. A, Atomic, Molecular, and Optical Physics, 72 . 063610. ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0506357v2
10.1103/PhysRevA.72.063610
oai:eprints.adm.unipi.it:1446
2013-08-06T11:12:05Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1446/
Fast Monte Carlo simulations and singularities in the probability distributions of non-equilibrium systems
Bandrivskyy, A.
Beri, S.
Luchinsky, D. G.
Mannella, R.
McClintock, P. V. E.
FIS/03 - Fisica della materia
SUMMARY A numerical technique is introduced that reduces exponentially the time
required for Monte Carlo simulations of non-equilibrium systems. Results for
the quasi-stationary probability distribution in two model systems are compared
with the asymptotically exact theory in the limit of extremely small noise
intensity. Singularities of the non-equilibrium distributions are revealed by
the simulations.
American Physical Society
2002-12-17
Article
PeerReviewed
Bandrivskyy, A. and Beri, S. and Luchinsky, D. G. and Mannella, R. and McClintock, P. V. E. (2002) Fast Monte Carlo simulations and singularities in the probability distributions of non-equilibrium systems. Physical review letters, 90 . p. 210201. ISSN 0031-9007
http://arxiv.org/abs/nlin/0212038v2
10.1103/PhysRevLett.90.210201
oai:eprints.adm.unipi.it:1447
2013-08-06T11:13:24Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1447/
Experiments on Critical Phenomena in a Noisy Exit Problem
Luchinsky, D. G.
Maier, R. S.
Mannella, R.
McClintock, P. V. E.
Stein, D. L.
FIS/03 - Fisica della materia
SUMMARY We consider noise-driven exit from a domain of attraction in a
two-dimensional bistable system lacking detailed balance. Through analog and
digital stochastic simulations, we find a theoretically predicted bifurcation
of the most probable exit path as the parameters of the system are changed, and
a corresponding nonanalyticity of the activation energy. We also investigate
the extent to which the bifurcation is related to the local breaking of
time-reversal invariance.
American Physical Society
1997
Article
PeerReviewed
Luchinsky, D. G. and Maier, R. S. and Mannella, R. and McClintock, P. V. E. and Stein, D. L. (1997) Experiments on Critical Phenomena in a Noisy Exit Problem. Physical review letters, 79 . p. 3109. ISSN 0031-9007
http://arxiv.org/abs/physics/9707002v1
10.1103/PhysRevLett.79.3109
oai:eprints.adm.unipi.it:1453
2013-09-10T15:27:33Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1453/
Linear Response Theory in Stochastic Resonance
Dykman, MI
Haken, H
Hu, Gang
Luchinsky, DG
Mannella, Riccardo
McClintock, PVE
Ning, CZ
Stein, ND
Stocks, NG
FIS/03 - Fisica della materia
SUMMARY The susceptibility of an overdamped Markov system fluctuating in a bistable
potential of general form is obtained by analytic solution of the Fokker-Planck
equation (FPE) for low noise intensities. The results are discussed in the
context of the LRT theory of stochastic resonance. They go over into recent
results (Gang Hu et al {\em Phys. Lett. A} {\bf 172}, 21, 1992) obtained from
the FPE for the case of a symmetrical potential, and they coincide with the LRT
results (Dykman et al, {\em Phys. Rev. Lett.} {\bf 65}, 2606, 1990; {\em JETP
Lett} {\bf 52}, 144, 1990; {\em Phys. Rev. Lett.} {\bf 68}, 2985, 1992)
obtained for the general case of bistable systems.
Elsevier Science
1993-08-09
Article
PeerReviewed
Dykman, MI and Haken, H and Hu, Gang and Luchinsky, DG and Mannella, Riccardo and McClintock, PVE and Ning, CZ and Stein, ND and Stocks, NG (1993) Linear Response Theory in Stochastic Resonance. Physics Letters A, 180 (4-5). pp. 332-336. ISSN 1873-2429
http://arxiv.org/abs/chao-dyn/9308002v1
10.1016/0375-9601(93)91186-9
oai:eprints.adm.unipi.it:1454
2013-09-10T15:28:01Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1454/
Noise-Induced Linearisation and Delinearisation
Dykman, MI
Luchinsky, DG
Mannella, Riccardo
McClintock, PVE
Short, HE
Stein, ND
Stocks, N G
FIS/03 - Fisica della materia
SUMMARY It is demonstrated, by means of analogue electronic simulation and
theoretically, that external noise can markedly change the character of the
response of a nonlinear system to a low-frequency periodic field. In general,
noise of sufficient intensity {\it linearises} the response. For certain
parameter ranges in particular cases, however, an increase in the noise
intensity can sometime have the opposite effect and is shown to {\it
delinearise} the response. The physical origins of these contrary behaviours
are discussed.
1993-12-09
Article
NonPeerReviewed
Dykman, MI and Luchinsky, DG and Mannella, Riccardo and McClintock, PVE and Short, HE and Stein, ND and Stocks, N G (1993) Noise-Induced Linearisation and Delinearisation. arXiv .
http://arxiv.org/abs/chao-dyn/9312005v2
oai:eprints.adm.unipi.it:1455
2013-08-06T10:51:54Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1455/
Activated escape of periodically driven systems
Dykman, M. I.
Golding, B.
McCann, L. I.
Smelyanskiy, V. N.
Luchinsky, D. G.
Mannella, R.
McClintock, P. V. E.
FIS/03 - Fisica della materia
SUMMARY We discuss activated escape from a metastable state of a system driven by a
time-periodic force. We show that the escape probabilities can be changed very
strongly even by a comparatively weak force. In a broad parameter range, the
activation energy of escape depends linearly on the force amplitude. This
dependence is described by the logarithmic susceptibility, which is analyzed
theoretically and through analog and digital simulations. A closed-form
explicit expression for the escape rate of an overdamped Brownian particle is
presented and shown to be in quantitative agreement with the simulations. We
also describe experiments on a Brownian particle optically trapped in a
double-well potential. A suitable periodic modulation of the optical intensity
breaks the spatio-temporal symmetry of an otherwise spatially symmetric system.
This has allowed us to localize a particle in one of the symmetric wells.
American Institute of Physics
2001
Article
PeerReviewed
Dykman, M. I. and Golding, B. and McCann, L. I. and Smelyanskiy, V. N. and Luchinsky, D. G. and Mannella, R. and McClintock, P. V. E. (2001) Activated escape of periodically driven systems. CHAOS, 11 . p. 587. ISSN 1089-7682
http://arxiv.org/abs/cond-mat/0110009v1
10.1063/1.1380368
oai:eprints.adm.unipi.it:1456
2013-08-06T10:54:05Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1456/
Chaotic ratchet dynamics with cold atoms in a pair of pulsed optical lattices
Carlo, Gabriel G.
Benenti, Giuliano
Casati, Giulio
Wimberger, Sandro
Morsch, Oliver
Mannella, Riccardo
Arimondo, Ennio
FIS/03 - Fisica della materia
SUMMARY We present a very simple model for realizing directed transport with cold
atoms in a pair of periodically flashed optical lattices. The origin of this
ratchet effect is explained and its robustness demonstrated under imperfections
typical of cold atom experiments. We conclude that our model offers a clear-cut
way to implement directed transport in an atom optical experiment.
American Physical Society
2006
Article
PeerReviewed
Carlo, Gabriel G. and Benenti, Giuliano and Casati, Giulio and Wimberger, Sandro and Morsch, Oliver and Mannella, Riccardo and Arimondo, Ennio (2006) Chaotic ratchet dynamics with cold atoms in a pair of pulsed optical lattices. Physical review. A, Atomic, Molecular, and Optical Physics, 74 . 033617. ISSN 1094-1622
http://arxiv.org/abs/cond-mat/0605695v2
10.1103/PhysRevA.74.033617
oai:eprints.adm.unipi.it:1461
2013-09-10T15:26:59Z
7374617475733D707562
7375626A656374733D417265613032:4649532F3033
74797065733D61727469636C65
http://eprints.adm.unipi.it/1461/
Stochastic Resonance
Dykman, M. I.
Luchinsky, D. G.
Mannella, R.
McClintock, P. V. E.
Soskin, S. M.
Stein, N. D.
Stocks, N. G.
FIS/03 - Fisica della materia
SUMMARY Stochastic resonance (SR) - a counter-intuitive phenomenon in which the
signal due to a weak periodic force in a nonlinear system can be {\it enhanced}
by the addition of external noise - is reviewed. A theoretical approach based
on linear response theory (LRT) is described. It is pointed out that, although
the LRT theory of SR is by definition restricted to the small signal limit, it
possesses substantial advantages in terms of simplicity, generality and
predictive power. The application of LRT to overdamped motion in a bistable
potential, the most commonly studied form of SR, is outlined. Two new forms of
SR, predicted on the basis of LRT and subsequently observed in analogue
electronic experiments, are described.
1993-07-17
Article
NonPeerReviewed
Dykman, M. I. and Luchinsky, D. G. and Mannella, R. and McClintock, P. V. E. and Soskin, S. M. and Stein, N. D. and Stocks, N. G. (1993) Stochastic Resonance. arXiv .
http://arxiv.org/abs/chao-dyn/9307006v1
metadataPrefix%3Doai_dc%26offset%3D1462%26set%3D7375626A656374733D417265613032