CRITICAL-BEHAVIOR OF THE 3D XY-MODEL - A MONTE-CARLO STUDY

We present the results of a study of the three-dimensional XY-model on a simple cubic lattice using the single cluster updating algorithm combined with improved estimators. We have measured the susceptibility and the correlation length for various couplings in the high temperature phase on lattices of size up to L = 112. At the transition temperature we studied the fourth-order cumulant and other cumulant-like quantities on lattices of size up to L = 64. From our numerical data we obtain for the critical coupling K(c) = 0.45420(2) and for the static critical exponents gamma/nu = 1.976(6) and nu = 0.662(7).