Quasi-classical Approach to Bose Condensation in a Finite Potential Well

TL;DR

This paper presents a quasi-classical approach to Bose condensation in finite potential wells, revealing a two-step condensation process and signatures of local condensation, with implications for exciton experiments.

Contribution

It introduces a self-consistent quasi-classical method to analyze Bose condensation in finite wells, highlighting a two-stage condensation process and local signatures.

Findings

Condensation occurs in two steps: in the well at low densities and in the bulk at higher densities.

Distribution of trapped particles shows distinct signatures of local condensation.

The approach connects theoretical predictions with recent exciton experiments.

Abstract

We treat the problem of self-consistently interacting bosons in the presence of a finite (but macroscopic) potential well within a quasi-classical approximation for the normal component and the order parameter. We solve the equilibrium problem and show, that actually condensation occurs in two steps. One already at low densities with Bose condensation only in the well and another one corresponding to the usual condensation in bulk. The peak and width of the distribution of trapped particles in the well display a distinct signature of the local condensation. A possible connection to recent experiments with excitons is discussed.