Work

Collective early-time spontaneous decay of a cold atomic ensemble from the single to multiple excitation regime

Year: 2026

Type: article

Abstract: In this work, we present a numerical and experimental investigation of the collective early-time decay rates of an optically dense cold atomic cloud supporting a large number of excitations. We prepare the atomic ensemble by driving the system to its steady state with varying Rabi frequencies Ω that go from the low excitation Ω ≪ Γ to the multiple excitation regime Ω ≫ Γ , where Γ is the single-atom decay rate. We investigate the early-time dynamics in the transition between the strong and weak driving regimes using (1) angular-dependent observables, such as the light emitted by the cloud, and (2) global observables, i.e., the excited-state population. When driving the cloud on resonance, we find that as a function of the driving frequency, the behavior of the collected light at certain angles transitions from the single-photon subradiant regime to a superradiant regime, while the behavior of the excited-state population does not show superradiance. The experiment shows good agreement with numerical predictions at the chosen angle of observation in the regime of parameters under study.

Source: Physical Review Research

DOI: 10.1103/kqr8-h1m5

Authors: Daniel Benedicto Orenes, Naudson Lucas Lopes Matias, Apoorva Apoorva, Antoine Glicenstein, Raphaël Saint-Jalm, Robin Kaiser