Body-assisted van der Waals interaction between excited atoms

TL;DR

This paper derives a formula for the van der Waals interaction between excited atoms in the presence of arbitrary material environments, addressing conflicting previous results and validating it against known cases.

Contribution

It introduces a new general formula for body-assisted van der Waals interactions involving excited atoms, incorporating arbitrary environments via Green functions.

Findings

The formula accounts for arbitrary material arrangements.

Validation against free space and dielectric sphere cases.

Addresses conflicting previous theoretical results.

Abstract

We present a formula for the body-assisted van der Waals interaction potential between two atoms, one or both being prepared in an excited energy eigenstate. The presence of arbitrary arrangement for material environment is taken into account via the Green function. The resulting formula supports one of two conflicting findings recorded. The consistency of our formula is investigated by applying it for the case of two atoms in free space and comparing the resulting expression with the one found from the limiting Casimir-Polder potential between an excited atom and a small dielectric sphere.