MONTE-CARLO STUDY OF ASYMMETRIC 2D XY MODEL

Employing the Polyakov-Susskind approximation in a field theoretical t reatment, the t-J model for strongly correlated electrons in two dimen sions has recently been shown to map effectively onto an asymmetric tw o-dimensional classical XY model. The critical temperature at which ch arge-spin separation occurs in the t-J model is determined by the loca tion of the phase transitions of this effective model. Here we report results of Monte Carlo simulations which map out the complete phase di agram in the two-dimensional parameter space and also shed some light on the critical behaviour of the transitions.