Impact of anisotropy on the interaction of an atom with a one-dimensional nano-grating

TL;DR

This paper investigates how anisotropy affects the atom's interaction with a one-dimensional nano-grating, revealing that strong anisotropy can induce a repulsive Casimir--Polder force.

Contribution

It derives the Green's tensor for the nano-grating considering anisotropy and analyzes its impact on the atom-grating Casimir--Polder potential.

Findings

Strong anisotropy can cause repulsive Casimir--Polder forces.

Green's tensor of the grating is derived using Rayleigh expansion.

Anisotropic contributions significantly influence atom-surface interactions.

Abstract

We study the interaction of an atom with a one-dimensional nano-grating within the framework of macroscopic QED, with special emphasis on possible anisotropic contributions. To this end, we first derive the scattering Green's tensor of the grating by means of a Rayleigh expansion and discuss its symmetry properties and asymptotes. We then determine the Casimir--Polder potential of an atom with the grating. In particular, we find that strong anisotropy can lead to a repulsive Casimir--Polder potential in the normal direction.