Interplay between polarization and quantum correlations of confined polaritons

TL;DR

This paper explores how polarization influences quantum correlations in confined polaritons, revealing new antibunching phenomena and suggesting experimental platforms like atomically thin semiconductors for strong quantum effects.

Contribution

It provides analytical and numerical analysis of polarization-dependent quantum correlations in a driven polariton cavity, highlighting regimes for strong antibunching and potential experimental realizations.

Findings

Both unconventional and conventional antibunchings can be observed in a single cavity.

Recent fiber-cavity polariton experiments likely probe cross-polarized interactions.

Large biexciton binding energies in semiconductors enhance polariton antibunching.

Abstract

We investigate polariton quantum correlations in a coherently driven box cavity in the low driving regime, with a particular focus on accounting for the polarization degree of freedom. The possibility of having different interaction strengths between co- and cross-circularly polarized polaritons as well as a realistic linear-polarization splitting allows one to model the system as two coupled nonlinear resonators with both self- and cross-Kerr-like nonlinearities, thus making our results potentially relevant for other experimental platforms. Within an effective wave-function approach, we obtain analytical expressions for the steady-state polarization-resolved polariton populations and second-order correlation functions, which agree very well with our numerical results obtained from a Lindblad master equation. Notably, we highlight that depending on the excitation polarization (circular or linear), both the unconventional (interference-mediated) and conventional (mediated by nonlinearities) antibunchings can be investigated in a single cavity. Moreover, using our results, we argue that recent experiments on confined fiber-cavity polaritons are likely to have probed a regime where the dominant interaction is between cross-polarized polaritons, which is characteristic of the polariton Feshbach resonance. We furthermore investigate the regime close to resonance using a two-channel model, and we show that systems with large biexciton binding energies, such as atomically thin semiconductors, are promising platforms for realizing strong polariton antibunching.