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

¹ Laboratoire de Physique Quantique, IRSAMC, Université Paul Sabatier, F-31062, Toulouse, Cedex 4, France
² Department of Physics, University of Waterloo - Waterloo, Ontario, N2L-3G1 Canada
³ Physics Department, Princeton University - Princeton, NJ 08544, USA

Received: 27 May 1998
Accepted: 24 September 1998

Abstract

The fixed-point structure of the 2D 3-state random-bond Potts model with a bimodal () distribution of couplings is fully determined using numerical renormalization group techniques. Along the paramagnet-to-ferromagnet critical line we find a total of four distinct fixed points: i) the pure critical fixed point, ii) the critical fixed point for the random-bond, but unfrustrated, ferromagnet, iii) a bicritical fixed point analogous to the bicritical Nishimori fixed point found in the random-bond frustrated Ising model, and iv) the zero-temperature spin-glass–to–ferromagnet critical fixed point. Estimates of the associated critical exponents are given for the various fixed points.