Phase transitions of the mean-field Potts glass model in a field

Yokota, Terufumi   

Phase transitions in the infinite-range p-state Potts glass model is studied in the presence of a field. Phase transition line into the transverse ordered phase is a straight line in a field-temperature phase diagram for small field and small effective ferromagnetic interaction. This is in contrast with the Gabay-Toulouse line for the vector spin-glass model. Replica symmetry breaking pattern is discussed near the phase transition line. Replica symmetry for the longitudinal order parameter is weakly broken at higher temperature than the transition line to the transverse ordered phase for p3.2. For p4.6, the transition to the transverse ordered phase reveals discontinuity in the order parameter just as the p4 case without a field.