Calabrese, Pasquale and Pelissetto, Andrea and Vicari, Ettore (2005) *Multicritical behavior in frustrated spin systems with noncollinear order.* Nuclear Physics B, 709 . p. 550. ISSN 0550-3213

## Abstract

We investigate the phase diagram and, in particular, the nature of the the multicritical point in three-dimensional frustrated $N$-component spin models with noncollinear order in the presence of an external field, for instance easy-axis stacked triangular antiferromagnets in the presence of a magnetic field along the easy axis. For this purpose we study the renormalization-group flow in a Landau-Ginzburg-Wilson \phi^4 theory with symmetry O(2)x[Z_2 +O(N-1)] that is expected to describe the multicritical behavior. We compute its MS \beta functions to five loops. For N\ge 4, their analysis does not support the hypothesis of an effective enlargement of the symmetry at the multicritical point, from O(2) x [Z_2+O(N-1)] to O(2)xO(N). For the physically interesting case N=3, the analysis does not allow us to exclude the corresponding symmetry enlargement controlled by the O(2)xO(3) fixed point. Moreover, it does not provide evidence for any other stable fixed point. Thus, on the basis of our field-theoretical results, the transition at the multicritical point is expected to be either continuous and controlled by the O(2)xO(3) fixed point or to be of first order.

Item Type: | Article |
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Additional Information: | Imported from arXiv |

Subjects: | Area02 - Scienze fisiche > FIS/02 - Fisica teorica, modelli e metodi matematici |

Divisions: | Dipartimenti (until 2012) > DIPARTIMENTO DI FISICA " E. FERMI" |

Depositing User: | dott.ssa Sandra Faita |

Date Deposited: | 09 Apr 2015 15:41 |

Last Modified: | 09 Apr 2015 15:41 |

URI: | http://eprints.adm.unipi.it/id/eprint/1802 |

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