Nested Open Quantum Systems Approach to Photonic Bose$-$Einstein Condensation

TL;DR

This paper develops a nested open quantum systems framework using macroscopic quantum electrodynamics to model photonic Bose-Einstein condensation, capturing complex geometry effects and dye-photon interactions.

Contribution

It introduces a novel nested open quantum systems approach that derives all key parameters for photon condensates of arbitrary shapes from Green's tensors.

Findings

Derived cavity mode absorption and emission rates for dye molecules.

Provided a comprehensive model for photon-dye dynamics in complex geometries.

Enabled description of photon condensates beyond simple cavity shapes.

Abstract

The photonic Bose$-$Einstein condensate is a recently observed collective ground state of a coupled light-matter system. We describe this quantum state based on macroscopic quantum electrodynamics in dispersing and absorbing environments. To model the coupled photon$-$dye dynamics, we derive a master equation using a nested open quantum systems approach yielding all parameters essential to describe the condensation process. This approach allows us to describe photon condensates of arbitrary shapes because all geometry-dependent decay constants can be expressed in terms of the Green's tensor. In particular, we obtain the cavity mode absorption and emission rates of the dye molecules.