Spectroscopic Effects of Velocity-Dependent Casimir-Polder Interactions Induced by Parallel Plates

TL;DR

This paper investigates how atomic velocity influences spectroscopic Casimir-Polder interactions between a moving atom and stationary plates, providing theoretical expressions and numerical analysis for specific atomic transitions.

Contribution

It introduces a feasible experimental setup analyzing velocity-dependent spectroscopic Casimir-Polder effects and derives their relation to Doppler shifts within a QED framework.

Findings

No significant velocity-dependent enhancement observed.

Spectroscopic effects are equivalent to Doppler-shifted static results under certain velocities.

Numerical analysis for Cs atom with sapphire plates provided.

Abstract

Casimir-Polder interactions cause energy and momentum exchange between microscopic and macroscopic bodies, a process mediated by quantum fluctuations in the coupled matter-electromagnetic field system. The dynamics of such effects are yet to be experimentally investigated due to the dominance of static effects at currently attainable atomic velocities. However, Y. Guo and Z. Jacob [\textit{Opt. Express}, 22:26193-26202, 2014] have proposed a non-static two-plate set-up where quantum fluctuation mediated effects have a strong velocity-dependent resonance, leading to a giant friction force on the plates. Here a more easily realisable set-up, a moving atom between two stationary plates, is analysed within a QED framework to establish the spectroscopic Casimir-Polder effects on the atom, and their velocity dependence. While no large velocity-dependent enhancement is found, expressions for the plate-induced spectroscopic effects on the atom were found, and further shown to be equivalent to the Doppler-shifted static result within certain velocity constraints. A numerical analysis investigates the behaviour of this system for the well studied case of the $6D_{3/2}\rightarrow 7P_{1/2}$ transition in $^{133}$Cs interacting with sapphire plates.