Dispersive interactions between atoms and non planar surfaces

TL;DR

This paper calculates the dispersive forces between a ground state atom and non planar surfaces, providing analytical and numerical results that improve understanding of atom-surface interactions beyond traditional approximations.

Contribution

It introduces a scattering approach to compute dispersive forces on non planar surfaces, including explicit results for corrugated surfaces and comparisons with the proximity force approximation.

Findings

Derived analytical results in different regimes

Numerically computed dispersive potentials for specific atom-surface configurations

Identified limitations of the proximity force approximation

Abstract

We calculate the dispersive force between a ground state atom and a non planar surface. We present explicit results for a corrugated surface, derived from the scattering approach at first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We discuss in detail the inadequacy of the proximity force approximation, and present a simple but adequate approximation for computing the potential.