Interface in a three dimensional XY model with a spatially varying coupling constant

Abstract

We have studied the three dimensional XY model with a nearest-neighbor coupling constant K varying linearly with position. In the region where K passes through its critical value there is an interface separating the ordered portion of the lattice from the disordered portion. We have used Monte Carlo simulations to elucidate the properties of this interface; in particular we have compared our results with the predictions of a simple scaling theory. This interface is analogous to one separating the superfluid and normal phases of liquid 4He in the presence of a gravitational field.