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Chiral critical behavior in two dimensions from five-loop renormalization-group expansions

P. Calabrese·E. V. Orlov·P. Parruccini·A. I. Sokolov
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Abstract

We analyse the critical behavior of two-dimensional N-vector spin systems with noncollinear order within the five-loop renormalization-group 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 $N \le N^*$, 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.

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P. Calabrese, E. V. Orlov, P. Parruccini, A. I. Sokolov. 2003-01-28. Chiral critical behavior in two dimensions from five-loop renormalization-group expansions. https://doi.org/10.1103/physrevb.67.024413

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