paper

Universal behavior of coupled order parameters below three dimensions

arXiv:1606.07449 · doi:10.1103/PhysRevE.94.042105

Abstract

We explore universal critical behavior in models with two competing order parameters, and an O(N)+O(M) symmetry for dimensions . In d=3, there is always exactly one stable Renormalization Group fixed point, corresponding to bicritical or tetracritical behavior. Employing novel, pseudo-spectral techniques to solve functional Renormalization Group equations in a two-dimensional field space, we uncover a more intricate structure of fixed points in d<3, where two additional bicritical fixed points play a role. Towards d=2, we discover ranges of N=M with several simultaneously stable fixed points, indicating the coexistence of several universality classes.

17 pages, 16 figures

References in corpus (68)

Cited by in corpus (14)