Condensation in hybrid superconducting cavity-microscopic spins systems with finite-bandwidth drive

TL;DR

This paper uses Keldysh field theory to determine conditions for non-equilibrium condensation in a driven open Tavis-Cummings model, highlighting experimental accessibility in hybrid superconducting systems with microscopic spins.

Contribution

It explicitly incorporates the drive's spectral distribution into the theoretical analysis, predicting the critical regime for condensation in driven hybrid light-matter systems.

Findings

Condensation transition depends on drive spectral distribution.

Incoherent photons induce a drive-dependent effective coupling.

Predicted critical regimes for non-equilibrium condensation.

Abstract

Using Keldysh field theory, we find conditions for non-equilibrium condensation in the open Tavis-Cummings model under a direct finite-bandwidth incoherent cavity drive. Experimentally, we expect the condensation transition to be easily accessible to hybrid superconducting systems coupled to microscopic spins, as well as to many other incoherently driven light-matter systems. In our theoretical analysis, we explicitly incorporate the drive's spectral distribution into the saddle-point description. We show that the injected incoherent photons create a drive-dependent effective coupling between spin-1/2 particles. The condensation transition arises at a critical regime of driving which we can now accurately predict. Our results also provide important guidelines for future quantum simulation experiments of non-equilibrium phases with hybrid devices.