Density-density correlation and interference mechanism for two initially independent Bose-Einstein condensates

TL;DR

This paper explores the interference mechanism of two initially independent Bose-Einstein condensates, proposing that density-density correlation measurements can distinguish between interaction-induced and measurement-induced interference theories.

Contribution

It introduces an analysis of the evolution of density-density correlations based on interaction-induced interference theory, highlighting differences from measurement-induced theory.

Findings

Density-density correlation shows emergence and disappearance of fringes over time.

Significant differences are found between the two interference theories.

Density-density correlation can experimentally reveal the interference mechanism.

Abstract

In an exciting experiment by MIT's group (Science 275, 637 (1997)), clear interference fringes were observed for two initially independent Bose condensates in dilute gas. Presently, there are two different theories (measurement-induced interference theory and interaction-induced interference theory) which can both explain MIT's experimental results. Based on our interaction-induced interference theory, we consider the evolution of the density-density correlation after the releasing of a double-well potential trapping two independent Bose condensates. Based on the interaction-induced interference theory, we find that the interference fringes in the density-density correlation exhibit a behavior of emergence and disappearance with the development of time. We find essential difference for the density-density correlation based on interaction-induced interference theory and measurement-induced interference theory, and thus we suggest the density-density correlation to experimentally reveal further the interference mechanism for two initially independent Bose condensates.