Casimir-Polder Potential of a Driven Atom

TL;DR

This paper theoretically analyzes how a laser-driven atom near a surface experiences a modified Casimir-Polder potential, comparing perturbative and Bloch equation approaches within macroscopic quantum electrodynamics.

Contribution

It introduces a comprehensive theoretical framework for the driven atom's Casimir-Polder potential, including an exact Bloch equation method and a perturbative approach for large detunings.

Findings

The driven atom's potential can be tuned to resemble the undriven case.

The Bloch equation approach provides an exact expression for the potential.

Perturbative approach is limited to large detunings.

Abstract

We investigate theoretically the Casimir-Polder potential of an atom which is driven by a laser field close to a surface. This problem is addressed in the framework of macroscopic quantum electrodynamics using the Green's tensor formalism and we distinguish between two different approaches, a perturbative ansatz and a method based on Bloch equations. We apply our results to a concrete example, namely an atom close to a perfectly conducting mirror, and create a scenario where the tunable Casimir-Polder potential becomes similar to the respective potential of an undriven atom due to fluctuating field modes. Whereas the perturbative approach is restricted to large detunings, the ansatz based on Bloch equations is exact and yields an expression for the potential which does not exceed 1/2 of the undriven Casimir-Polder potential.