Cavity exciton-polaritons in two-dimensional semiconductors from first principles

TL;DR

This paper uses first-principles calculations to study exciton-polariton formation in 2D semiconductors within microcavities, revealing tunable strong coupling and predicting large Rabi splittings in specific materials.

Contribution

It introduces a first-principles propagator method to analyze exciton-photon coupling in 2D semiconductors, enabling accurate prediction of Rabi splittings and potential for designing polariton-based devices.

Findings

Maximum Rabi splitting of 128 meV in phosphorene cavity

Predicted Rabi splitting of about 440 meV in monolayer hBN

Excellent agreement with recent experimental results in WS$_2$ microcavity

Abstract

Two-dimensional (2D) semiconducting microcavity, where exciton-polaritons can be formed, constitues a promising setup for exploring and manipulating various regimes of light-matter interaction. Here, the coupling between 2D excitons and metallic cavity photons is studied by using first-principles propagator technique. The strength of exciton-photon coupling is characterised by its Rabi splitting to two exciton-polaritons, which can be tuned by cavity thickness. Maximum splitting of 128 meV is achieved in phosporene cavity, while remarkable value of about 440 meV is predicted in monolayer hBN device. The obtained Rabi splittings in WS$_2$ microcavity are in excellent agreement with the recent experiments. Present methodology can aid in predicting and proposing potential setups for trapping robust 2D exciton-polariton condensates.