Probing interactions between Rydberg atoms with large electric dipole moments in amplitude modulated electric fields

TL;DR

This study investigates dipole-dipole interactions among helium Rydberg atoms with large electric dipole moments under amplitude-modulated electric fields, revealing how these interactions influence spectral properties and potential sensing applications.

Contribution

It provides the first experimental analysis of dipole-dipole interactions in helium Rydberg-Stark states with large dipole moments under RF modulation, supported by Floquet calculations.

Findings

Spectral intensity distributions change due to dipole-dipole interactions.

Excellent agreement between experimental data and Floquet calculations.

Demonstration of Rydberg states as broadband RF noise sensors.

Abstract

Dipole-dipole interactions between helium atoms in Rydberg-Stark states with principal quantum number $n=53$ and approximately linear Stark energy shifts, resulting from induced electric dipole moments of approximately 7900 D, have been investigated experimentally. The experiments were performed in pulsed supersonic metastable helium beams, with particle number densities of up to $\sim10^9$ cm$^{-3}$. In the presence of amplitude-modulated, radio-frequency electric fields, changes in the spectral intensity distributions associated with the transitions to these states that are attributed to dipole-dipole interactions within the ensembles of excited atoms have been observed. The experimental results are in excellent agreement with calculations of the Rydberg energy level structure carried out using Floquet methods, and excitations shared by up to 4 atoms. The use of these Rydberg-Stark states as sensors for non-resonant broadband radio-frequency electrical noise is also discussed.