Phase transitions in the Potts spin-glass model

We have studied the Potts spin glass with two-state Ising spins and s -state Potts variables using a cluster Monte Carlo dynamics. The model recovers the ± J Ising spin glass (SG) for s = 1 and exhibits for all s a SG transition at T SG ( s ) and a percolation transition at higher temperature T p ( s ) . We have shown that for all values of s ≠ 1 at T p ( s ) there is a thermodynamic transition in the universality class of a ferromagnetic s -state Potts model. The efficiency of the cluster dynamics is compared with that of standard spin-flip dynamics