Implementation of the Dicke lattice model in hybrid quantum system arrays

TL;DR

This paper demonstrates how to implement and analyze the Dicke lattice model in hybrid quantum systems using NV centers in diamond coupled to microwave cavities, revealing observable superradiant phase transitions.

Contribution

It introduces a tunable implementation of the Dicke lattice model in hybrid quantum systems and analyzes the resulting non-equilibrium phases and phase transitions.

Findings

Superradiant phase transitions are observable with current technology.

Distinct features in the phase diagram are induced by dissipation.

Large inhomogeneous broadening does not prevent phase transition observation.

Abstract

Generalized Dicke models can be implemented in hybrid quantum systems built from ensembles of nitrogen-vacancy (NV) centers in diamond coupled to superconducting microwave cavities. By engineering cavity assisted Raman transitions between two spin states of the NV defect, a fully tunable model for collective light-matter interactions in the ultra-strong coupling limit can be obtained. Our analysis of the resulting non-equilibrium phases for a single cavity and for coupled cavity arrays shows that different superradiant phase transitions can be observed using existing experimental technologies, even in the presence of large inhomogeneous broadening of the spin ensemble. The phase diagram of the Dicke lattice model displays distinct features induced by dissipation, which can serve as a genuine experimental signature for phase transitions in driven open quantum systems.