Superradiant Quantum Materials

TL;DR

This paper demonstrates how strong electron interactions and photon-induced correlations in quantum materials can stabilize novel coherent phases involving both exciton condensation and photon superradiance, revealing new collective phenomena.

Contribution

It introduces a two-band model showing the emergence of a phase with intertwined exciton and photon superradiance due to cooperative effects.

Findings

Realization of a phase with simultaneous exciton condensation and superradiance

Cooperative effects stabilize and intertwine collective light-matter phenomena

Potential for new quantum states in strongly coupled light-matter systems

Abstract

There is currently great interest in the strong coupling between the quantized photon field of a cavity and electronic or other degrees of freedom in materials. A major goal is the creation of novel collective states entangling photons with those degrees of freedom. Here we show that the cooperative effect between strong electron interactions in quantum materials and the long-range correlations induced by the photon field leads to the stabilization of coherent phases of light and matter. By studying a two-band model of interacting electrons coupled to a cavity field, we show that a phase characterized by the simultaneous condensation of excitons and photon superradiance can be realized, hence stabilizing and intertwining two collective phenomena which are rather elusive in the absence of this cooperative effect.