Southwest Quantum Information and Technology

Universality of Dicke superradiance in arrays of quantum emitters

Presenting Author: Stuart Masson, Columbia University
Contributing Author(s): Ana Asenjo-Garcia

Collective effects in subwavelength atomic ensembles lead to exotic optical properties that have begun to be explored in experimental systems. Here, we investigate the physics of collective decay in ordered atomic systems, going beyond single-excitation phenomena. The decay of a fully inverted ensemble of atoms at the same spatial location is well known: the emitted light initially grows in intensity and photons are emitted in a short burst, so-called Dicke superradiance. However, atoms separated by large distances act independently and their decay is exponential, monotonically decreasing in time. We connect these separate regimes by considering mesoscopic atomic arrays. We show that the superradiant burst survives at small interatomic distances, though with a reduced amplitude, and late decay becomes strongly subradiant and directional. As the interatomic separation is increased, the size of the burst decreases, eventually disappearing. The crossover between these regimes can be identified solely by investigating very early dynamics. We also derive a concise expression -- which is applicable to arrays of any dimensionality and topology -- that allows us to predict the critical distance beyond which superradiance disappears. This allows for predictions to be made for large atom numbers, and identification of geometries where this physics could be probed experimentally.

Read this article online: https://arxiv.org/abs/2106.02042

(Session 5 : Thursday from 12:00pm-2:00 pm)