Boundary of two mixed Bose-Einstein condensates

Abstract

We study the boundary between two interpenetrating Bose-Einstein condensates interacting repulsively in the case of their spatial separation. We show that the analytical expressions for the distribution of the condensate density can be obtained in the limiting cases corresponding to the weak and strong separations. Using these expressions, we consider the excitation spectrum of a particle confined in the vicinity of the boundary and the surface waves at the boundary.