Equilibrium and Disorder-induced behavior in Quantum Light-Matter Systems

TL;DR

This paper investigates the equilibrium properties of coupled-doped cavities using the Jaynes-Cummings-Hubbard model, revealing phase transitions, disorder effects, and glassy phases in quantum light-matter systems.

Contribution

It introduces a detailed analysis of disorder-induced phenomena and phase crossover in quantum light-matter systems, combining statistical and mean-field approaches.

Findings

Identification of a crossover from polaritonic to photonic excitations within the superfluid phase.

Discovery of glassy phases arising from disorder in system parameters.

Mechanisms of disorder-induced insulating behavior in light-matter systems.

Abstract

We analyze equilibrium properties of coupled-doped cavities described by the Jaynes-Cummings- Hubbard Hamiltonian. In particular, we characterize the entanglement of the system in relation to the insulating-superfluid phase transition. We point out the existence of a crossover inside the superfluid phase of the system when the excitations change from polaritonic to purely photonic. Using an ensemble statistical approach for small systems and stochastic-mean-field theory for large systems we analyze static disorder of the characteristic parameters of the system and explore the ground state induced statistics. We report on a variety of glassy phases deriving from the hybrid statistics of the system. On-site strong disorder induces insulating behavior through two different mechanisms. For disorder in the light-matter detuning, low energy cavities dominate the statistics allowing the excitations to localize and bunch in such cavities. In the case of disorder in the light- matter coupling, sites with strong coupling between light and matter become very significant, which enhances the Mott-like insulating behavior. Inter-site (hopping) disorder induces fluidity and the dominant sites are strongly coupled to each other.