Evaporative Cooling of a Photon Fluid to Quantum Degeneracy

TL;DR

This paper shows that evaporative cooling can be applied to photon systems in a cavity to achieve quantum degeneracy, leading to coherent light similar to Bose-Einstein condensates.

Contribution

It introduces a method to condense photons via evaporative cooling in a cavity, a novel approach extending atomic cooling techniques to light.

Findings

Predicted macroscopic occupation of the lowest energy photon mode

Identified conditions for narrow spectral width and long coherence time

Demonstrated feasibility of photon condensation through evaporative cooling

Abstract

We demonstrate that the process of evaporative cooling, as associated with the cooling of atomic gases, can also be employed to condense a system of photons giving rise to coherent properties of the light. The system we study consists of photons in a high-quality Fabry-Perot cavity with photon interactions mediated by a nonlinear atomic medium. We predict a macroscopic occupation of the lowest energy mode and evaluate the conditions for realizing a narrow spectral width indicative of a long coherence time for the field.