Biconical critical dynamics

TL;DR

This paper performs a detailed two-loop renormalization group analysis of multicritical dynamics in anisotropic antiferromagnets, revealing persistent differences in effective dynamical exponents despite restored strong scaling.

Contribution

It provides a comprehensive two-loop RG calculation of multicritical dynamics, highlighting the behavior of effective exponents in experimentally relevant regions.

Findings

Strong scaling is restored for the two order parameters.

Effective dynamical exponents remain different in accessible regions.

Asymptotic exponents are equal only at very large scales.

Abstract

A complete two loop renormalization group calculation of the multicritical dynamics at a tetracritical or bicritical point in anisotropic antiferromagnets in an external magnetic field is performed. Although strong scaling for the two order parameters (OPs) perpendicular and parallel to the field is restored as found earlier, in the experimentally accessible region the effective dynamical exponents for the relaxation of the OPs remain different since their equal asymptotic values are not reached.