Non-trivial fixed point structure of the two-dimensional +-J 3-state Potts ferromagnet/spin glass

TL;DR

This paper fully determines the fixed point structure of the 2D 3-state random-bond Potts model with bimodal couplings, revealing multiple non-trivial fixed points and estimating their critical exponents using numerical renormalization group techniques.

Contribution

First complete identification of all fixed points in the 2D 3-state random-bond Potts model with bimodal couplings, including critical and bicritical points, with critical exponent estimates.

Findings

Identification of pure, T=0, and two non-trivial fixed points.

Discovery of a bicritical fixed point similar to Nishimori point.

Estimation of critical exponents for all fixed points.

Abstract

The fixed point structure of the 2D 3-state random-bond Potts model with a bimodal ($\pm$J) distribution of couplings is for the first time fully determined using numerical renormalization group techniques. Apart from the pure and T=0 critical fixed points, two other non-trivial fixed points are found. One is the critical fixed point for the random-bond, but unfrustrated, ferromagnet. The other is a bicritical fixed point analogous to the bicritical Nishimori fixed point found in the random-bond frustrated Ising model. Estimates of the associated critical exponents are given for the various fixed points of the random-bond Potts model.