Interference effects between two initially independent Bose-condensed gases

TL;DR

This paper investigates how interactions induce coherence and interference effects between two initially independent Bose-condensed gases when they overlap, revealing a nonzero interference term due to interatomic interactions.

Contribution

It demonstrates that interatomic interactions lead to a nonzero interference term and coherence between initially independent Bose condensates, using an exact density expectation value analysis.

Findings

Interaction induces coherence between independent condensates

Nonzero interference term appears due to interactions

Density evolution varies with coupling strength

Abstract

When two initially independent Bose-condensed gases are allowed to overlap, we investigate the density expectation value of the whole system by using the second quantization method. In the presence of interatomic interaction, based on the exact expression of the density expectation value, it is found that there is a nonzero interference term in the density expectation value of the whole system. The evolution of the density expectation value is shown for different coupling constants. The present work shows clearly that there is an interaction-induced coherence process between two initially independent condensates.