Interaction of Impurity Atoms in Bose-Einstein-Condensates

TL;DR

This paper investigates how impurity atoms interact via phonon exchange in a Bose-Einstein condensate, revealing energy shifts and interaction mechanisms using a Bogoliubov theoretical framework.

Contribution

It provides a detailed theoretical analysis of impurity-impurity interactions mediated by phonons in a BEC, including energy shifts and exchange effects.

Findings

Impurity atoms experience level shifts from mean-field and vacuum contributions.

Phonon exchange induces a conditional energy shift between impurity atoms.

The study advances understanding of impurity interactions in quantum gases.

Abstract

The interaction of two spatially separated impurity atoms through phonon exchange in a Bose-Einstein condensate is studied within a Bogoliubov approach. The impurity atoms are held by deep and narrow trap potentials and experience level shifts which consist of a mean-field part and vacuum contributions from the Bogoliubov-phonons. In addition there is a conditional energy shift resulting from the exchange of phonons between the impurity atoms.