Rabi Interferometry and Sensitive Measurement of the Casimir-Polder Force with Ultra-Cold Gases

TL;DR

This paper proposes using Rabi oscillations in ultra-cold gases within a double-well potential for interferometric force measurements at micrometer scales, specifically targeting the Casimir-Polder force, with potential for high sensitivity even with small atom numbers.

Contribution

It introduces a Rabi interferometer as a simpler alternative to Mach-Zehnder setups for force sensing, demonstrating its application to measure the Casimir-Polder force with realistic experimental conditions.

Findings

Rabi interferometry can detect Casimir-Polder forces at micrometer distances.

Small atom number states can achieve sufficient sensitivity.

Spin squeezed states can further enhance measurement precision.

Abstract

We show that Rabi oscillations of a degenerate fermionic or bosonic gas trapped in a double-well potential can be exploited for the interferometric measurement of external forces at micrometer length scales. The Rabi interferometer is less sensitive, but easier to implement, than the Mach-Zehnder since it does not require dynamical beam-splitting/recombination processes. As an application we propose a measurement of the Casimir-Polder force acting between the atoms and a dielectric surface. We find that even if the interferometer is fed with a coherent state of relatively small number of atoms, and in the presence of realistic experimental noise, the force can be measured with a sensitivity sufficient to discriminate between thermal and zero-temperature regimes of the Casimir-Polder potential. Higher sensitivities can be reached with spin squeezed states.