FINITE-SIZE-SCALING STUDY OF THE VORTEX-FREE 3-DIMENSIONAL XY MODEL

Monte Carlo simulations have been used to study a version of the XY model without vortex loops for J/T = 0 on simple cubic and face-centered-cubic lattices. Finite-size scaling of data from L X L X L lattices with L up to 32 is used to obtain values for the order parameter \M\ and a 1/L finite-size correction on each lattice. The order-parameter susceptibility is found to be diverging as L(0.8). We then study the crossover from three-dimensional to one-dimensional behavior on L X W X W simple cubic lattices, with W = 4 and 8, and L up to 1024.