Polaron-Polaritons in the Integer and Fractional Quantum Hall Regimes

TL;DR

This paper investigates how electron-exciton interactions in two-dimensional electron systems are affected by strong correlations in quantum Hall regimes, revealing modifications in polariton behavior and potential for enhanced polariton interactions.

Contribution

It provides the first cavity spectroscopy analysis of polariton resonances in strongly correlated quantum Hall phases, highlighting the impact of electron filling factors on polariton properties.

Findings

Modification of electron-exciton interactions at different filling factors

Observation of phase space filling effects at integer filling factors

Detection of polaron dressing phenomena at fractional filling factors

Abstract

Elementary quasi-particles in a two dimensional electron system can be described as exciton-polarons since electron-exciton interactions ensures dressing of excitons by Fermi-sea electron-hole pair excitations. A relevant open question is the modification of this description when the electrons occupy flat-bands and electron-electron interactions become prominent. Here, we perform cavity spectroscopy of a two dimensional electron system in the strong-coupling regime where polariton resonances carry signatures of strongly correlated quantum Hall phases. By measuring the evolution of the polariton splitting under an external magnetic field, we demonstrate the modification of electron-exciton interactions that we associate with phase space filling at integer filling factors and polaron dressing at fractional filling factors. The observed non-linear behavior shows great promise for enhancing polariton-polariton interactions.