Coherent Population Trapping with Controlled Interparticle Interactions

TL;DR

This paper explores how coherent population trapping persists in a strongly interacting ultracold Rydberg gas, revealing many-body effects beyond mean-field theories and demonstrating the importance of interparticle correlations.

Contribution

It provides experimental evidence and a theoretical framework showing the persistence of narrow resonances in strongly interacting Rydberg gases, challenging mean-field models.

Findings

Persistence of subnatural linewidth resonance despite strong interactions

Mean-field models fail to explain the observed spectral features

Many-body density matrix approach successfully reproduces experimental results

Abstract

We investigate Coherent Population Trapping in a strongly interacting ultracold Rydberg gas. Despite the strong van der Waals interactions and interparticle correlations, we observe the persistence of a resonance with subnatural linewidth at the single-particle resonance frequency as we tune the interaction strength. This narrow resonance cannot be understood within a meanfield description of the strong Rydberg--Rydberg interactions. Instead, a many-body density matrix approach, accounting for the dynamics of interparticle correlations, is shown to reproduce the observed spectral features.