Numerical Study of a Superconducting Glass Model

A random gauge XY model as a model for a superconducting glass is studied at zero temperature in two and three dimensions by finite size scaling of both defect energy and disorder strength with increasing length scale. Weak disorder is found to be marginal in two and probably irrelevant in three dimensions. For strong disorder the flow is toward a nonsuperconducting gauge glass fixed point in 2D and a superconducting glass in 3D. Our results are in agreement with recent analytic theory and are inconsistent with earlier predictions of a reentrant transition to a disordered phase at very low temperature and with the loss of superconductivity for any finite amount of disorder.