Optomechanical Rydberg-atom excitation via dynamic Casimir-Polder coupling

TL;DR

This paper explores a novel optomechanical coupling mechanism between a driven mirror and Rydberg atoms via the dynamical Casimir-Polder force, enabling near-field atomic excitation detectable in cold atom experiments.

Contribution

It introduces a new method to induce atomic excitation through dynamical Casimir-Polder coupling mediated by a periodically driven substrate acting as a mechanical mirror.

Findings

Atomic excitation probability scales as (d^2 a n^4 t)^2 / z_0^8.

Proposed setup can excite about 100 Rydberg atoms in 0.5 microseconds.

Feasible with current cold atom experimental conditions.

Abstract

We study the optomechanical coupling of a oscillating effective mirror with a Rydberg atomic gas, mediated by the dynamical atom-mirror Casimir-Polder force. This coupling may produce a near-field resonant atomic excitation whose probability scales as $\propto (d^2\;a\;n^4\;t)^2/z_0^8$, where $z_0$ is the average atom-surface distance, $d$ the atomic dipole moment, $a$ the mirror's effective oscillation amplitude, $n$ the initial principal quantum number, and $t$ the time. We propose an experimental configuration to realize this system with a cold atom gas trapped at a distance $\sim 2\cdot10 \, \mu$m from a semiconductor substrate, whose dielectric constant is periodically driven by an external laser pulse, hence realizing en effective mechanical mirror motion due to the periodic change of the substrate from transparent to reflecting. For a parabolic gas shape, this effect is predicted to excite about $\sim 10^2$ atoms of a dilute gas of $10^3$ trapped Rydberg atoms with $n=75$ after about $0.5 \,\mu \mbox{s}$, hence high enough to be detected in typical Rydberg gas experimental conditions.