Three-dimensional randomXYmodel: Application to the superfluid transition ofHe4in porous media

Abstract

We study a three-dimensional classical XY model with strongly fluctuating, spatially uncorrelated, bond disorder. Finite-size scaling analysis of Monte Carlo simulation data has been used to determine critical exponents. Evidence for a possible shift in exponents from the pure XY case is found. Connection to recent experiments on the superfluid phase transition of ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ in porous media is discussed.