Non-equilibrium quantum condensation in an incoherently pumped dissipative system

TL;DR

This paper investigates non-equilibrium quantum condensation in a dissipative system with incoherent pumping and decay, revealing stable steady states with unique spectral properties distinct from traditional condensates and lasers.

Contribution

It introduces a theoretical framework for understanding quantum coherence in out-of-equilibrium systems with multiple baths, highlighting how pumping and decay alter phase fluctuation spectra.

Findings

Stable steady-state condensed solutions exist under certain bath coupling conditions.

Spectral properties of phase fluctuations differ from those in isolated condensates and lasers.

Pumping and decay significantly influence the coherence and fluctuation behavior.

Abstract

We study spontaneous quantum coherence in an out of equilibrium system, coupled to multiple baths describing pumping and decay. For a range of parameters describing coupling to, and occupation of the baths, a stable steady-state condensed solution exists. The presence of pumping and decay significantly modifies the spectra of phase fluctuations, leading to correlation functions that differ both from an isolated condensate and from a laser.