Probing subradiant dynamics in cold atomic ensembles via population and emitted light measurements

TL;DR

This paper demonstrates direct measurement of subradiant states in cold ytterbium atoms using a novel imaging technique, revealing decay dynamics that match theoretical predictions and advancing understanding of collective atomic behaviors.

Contribution

It introduces a depletion imaging method to directly observe subradiant populations and their decay in cold atomic ensembles, providing new insights into collective light-matter interactions.

Findings

Good agreement between experimental data and numerical simulations

Direct visualization of spatial distribution of subradiant states

Quantitative characterization of decay dynamics

Abstract

In this letter, we report on the time- and space-resolved measurement of subradiant excited state population in an ultra-cold atomic cloud of 174Yb atoms. We use a depletion imaging technique that exploits the V-type internal energy structure of alkaline-earth-like atoms to directly observe the time-resolved spatial distribution of excited state population. We characterize the decay dynamics of the subradiant modes using both the excited state population and scattered light intensity, finding good quantitative agreement with numerical predictions from simulations of two-level atomic ensembles.