We analyze the critical behavior of two-dimensional N-vector spin systems with noncollinear order within the five-loop renormalization-group (RG) approximation. The structure of the RG flow is studied for different N leading to the conclusion that the chiral fixed point governing the critical behavior of physical systems with N=2 and N=3 does not coincide with that given by the 1/N expansion. We show that the stable chiral fixed point for Nless than or equal toN(*), including N=2 and N=3, turns out to be a focus. We give a complete characterization of the critical behavior controlled by this fixed point, also evaluating the subleading crossover exponents. The spiral-like approach of the chiral fixed point is argued to give rise to unusual crossover and near-critical regimes that may imitate varying critical exponents seen in numerous physical and computer experiments.

Chiral critical behavior of frustrated spin systems in two dimensions from five-loop renormalization-group expansions

Calabrese, Pasquale;
2003-01-01

Abstract

We analyze the critical behavior of two-dimensional N-vector spin systems with noncollinear order within the five-loop renormalization-group (RG) approximation. The structure of the RG flow is studied for different N leading to the conclusion that the chiral fixed point governing the critical behavior of physical systems with N=2 and N=3 does not coincide with that given by the 1/N expansion. We show that the stable chiral fixed point for Nless than or equal toN(*), including N=2 and N=3, turns out to be a focus. We give a complete characterization of the critical behavior controlled by this fixed point, also evaluating the subleading crossover exponents. The spiral-like approach of the chiral fixed point is argued to give rise to unusual crossover and near-critical regimes that may imitate varying critical exponents seen in numerous physical and computer experiments.
2003
67
2
Calabrese, Pasquale; Orlov, Ev; Parruccini, P; Sokolov, Ai
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11767/13776
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