Ramsey interferometry of Rydberg ensembles inside microwave cavities

TL;DR

This paper investigates how Rydberg atom ensembles inside microwave cavities exhibit varied interaction regimes, and uses Ramsey spectroscopy to characterize these interactions, revealing significant effects at lower densities than previously possible.

Contribution

It introduces a method to analyze cavity-mediated Rydberg interactions via Ramsey spectroscopy, highlighting new regimes and lower density operation.

Findings

Interaction regimes range from van der Waals to linear with distance.

Cavity environment enables observable effects at lower densities.

Ramsey signals effectively map two-body interactions.

Abstract

We study ensembles of Rydberg atoms in a confined electromagnetic environment such as provided by a microwave cavity. The competition between standard free space Ising type and cavity-mediated interactions leads to the emergence of different regimes where the particle-particle couplings range from the typical van der Waals $r^{-6}$ behavior to $r^{-3}$ and to $r$-independence. We apply a Ramsey spectroscopic technique to map the two-body interactions into a characteristic signal such as intensity and contrast decay curves. As opposed to previous treatments requiring high-densities for considerable contrast and phase decay, the cavity scenario can exhibit similar behavior at much lower densities.