Atom-wall dispersive forces: a microscopic approach

TL;DR

This paper develops a microscopic quantum electrodynamics approach to atom-wall forces, unifying various known forces and revealing new low-temperature corrections when electrostatic interactions are screened.

Contribution

It introduces a functional integral method that incorporates radiation field interactions, deriving known forces and identifying novel low-temperature effects beyond Lifshitz theory.

Findings

Retrieves van der Waals, Casimir-Polder, and Lifshitz forces within the formalism.

Identifies low-temperature corrections in screened media.

Provides a unified microscopic framework for atom-wall interactions.

Abstract

We present a study of atom-wall interactions in non-relativistic quantum electrodynamics by functional integral methods. The Feynman-Kac path integral representation is generalized to the case when the particle interacts with a radiation field, providing an additional effective potential that contains all the interactions induced by the field. We show how one can retrieve the standard van der Waals, Casimir-Polder and classical Lifshiftz forces in this formalism for an atom in its ground state. Moreover, when electrostatic interactions are screened in the medium, we find low temperature corrections that are not included in the Lifshitz theory of fluctuating forces and are opposite to them.