Thermodynamic and critical properties of dilute XY magnets: Monte Carlo study

The thermodynamic and critical properties of two dimensional dilute XY spin magnets on a triangular lattice are studied by using a hybrid Monte Carlo method. The critical temperatures of different non-magnetic impurity densities are obtained by two types of methods, including finite-size scaling of plane magnetic susceptibility and helicity modulus. It is found that the dilution plays an important effect on the critical temperature and thermodynamic equilibrium properties. The critical temperature decreases with the increase of magnetic impurity density ρ and the BKT phase transition vanishes at the site percolation threshold p c = 0.5 .