Polaritonic properties of the Jaynes-Cummings lattice model in two dimensions

TL;DR

This paper investigates the two-dimensional Jaynes-Cummings lattice model, analyzing quantum phase transitions and polaritonic properties by characterizing spectral features and defining polariton quasiparticles as superpositions of photons and atomic excitations.

Contribution

It introduces a detailed spectral analysis and a novel definition of polariton quasiparticles in the 2D Jaynes-Cummings lattice model, advancing understanding of light-matter interactions.

Findings

Identified the boundary of the quantum phase transition.

Characterized spectral properties of photons and two-level excitations.

Defined polariton quasiparticles as superpositions with constituent contributions.

Abstract

Light-matter systems allow to realize a strongly correlated phase where photons are present. In these systems strong correlations are achieved by optical nonlinearities, which appear due to the coupling of photons to atomic-like structures. This leads to intriguing effects, such as the quantum phase transition from the Mott to the superfluid phase. Here, we address the two-dimensional Jaynes-Cummings lattice model. We evaluate the boundary of the quantum phase transition and study polaritonic properties. In order to be able to characterize polaritons, we investigate the spectral properties of both photons as well as two-level excitations. Based on this information we introduce polariton quasiparticles as appropriate wavevector, band index, and filling dependent superpositions of photons and two-level excitations. Finally, we analyze the contributions of the individual constituents to the polariton quasiparticles.