Critical behaviour of the 3D XY-model: A Monte Carlo study

We present the results of a study of the three-dimensional XY-model 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 1123. In the neighbourhood of the critical temperature we studied the Binder-cumulant and other cumulant like quantities on lattices of size up to 643. From our accurate numerical data we obtain for the critical coupling Kc = 0.45420(2), for the static critical exponents γ/ν = 1.975(6), ν = 0.662(7) at criticality and for the susceptibility exponent γ = 1.324(1) in the high temperature phase.