Non-Equilibrium Bose-Einstein Condensation in a Dissipative Environment

TL;DR

This paper develops a non-equilibrium path integral framework to study Bose-Einstein condensation in dissipative systems like microcavity polaritons, highlighting differences from equilibrium condensates and connecting to lasing phenomena.

Contribution

It introduces a novel non-equilibrium path integral approach for condensates in dissipative environments, specifically applied to microcavity polaritons driven by multiple baths.

Findings

Established a theoretical link between non-equilibrium polariton condensation and lasing.

Demonstrated the role of external pumping and decay in steady-state condensation.

Provided insights into the relation between non-equilibrium and equilibrium condensates.

Abstract

Solid state quantum condensates can differ from other condensates, such as Helium, ultracold atomic gases, and superconductors, in that the condensing quasiparticles have relatively short lifetimes, and so, as for lasers, external pumping is required to maintain a steady state. In this chapter we present a non-equilibrium path integral approach to condensation in a dissipative environment and apply it to microcavity polaritons, driven out of equilibrium by coupling to multiple baths, describing pumping and decay. Using this, we discuss the relation between non-equilibrium polariton condensation, lasing, and equilibrium condensation.