Two-photon superradiance and subradiance

TL;DR

This paper explores two-photon cooperative emission phenomena in atomic systems, analyzing superradiance and subradiance in small atom groups and in continuous atomic densities within spherical volumes, revealing different regimes of collective emission.

Contribution

It provides a detailed analysis of two-photon super- and sub-radiant states across different atomic configurations and sizes, highlighting new insights into collective emission behaviors.

Findings

Identification of superradiant and subradiant states in small atomic systems

Analysis of emission spectra depending on atomic density and geometry

Distinct behaviors observed for small versus large spherical volumes

Abstract

We consider the problem of two-photon cooperative emission in systems of two-level atoms. Two physically distinct regimes are analyzed. First, we investigate the case of a small number of atoms. We study the evolution of two-photon super- and sub-radiant states and associated two-photon spectra. Second, we investigate the problem of a constant density of atoms confined to a spherical volume. We analyze separately the cases in which the radius is small or large in comparison to the resonant wavelength.