Photonic Architectures for Equilibrium High-Temperature Bose-Einstein Condensation in Dichalcogenide Monolayers

TL;DR

This paper proposes a theoretical design for photonic structures that enable equilibrium Bose-Einstein condensation of polaritons at temperatures above room temperature, using dichalcogenide monolayers in 3D photonic band gap materials.

Contribution

It introduces a novel photonic architecture with strong light-trapping capabilities that achieve high-temperature polariton BEC in monolayer materials.

Findings

Achieves above-room-temperature BEC of polaritons in MoSe2 monolayers.

Demonstrates strong light-matter coupling with 40 meV Rabi splitting.

Shows robustness of polariton superfluid against disorder.

Abstract

Semiconductor-microcavity polaritons are composite quasiparticles of excitons and photons, emerging in the strong coupling regime. As quantum superpositions of matter and light, polaritons have much stronger interparticle interactions compared with photons, enabling rapid equilibration and Bose-Einstein condensation (BEC). Current realizations based on 1D photonic structures, such as Fabry-P\'erot microcavities, have limited light-trapping ability resulting in picosecond polariton lifetime. We demonstrate, theoretically, above-room-temperature (up to 590 K) BEC of long-lived polaritons in MoSe$_2$ monolayers sandwiched by simple TiO$_2$ based 3D photonic band gap (PBG) materials. The 3D PBG induces very strong coupling of 40 meV (Rabi splitting of 62 meV) for as few as three dichalcogenide monolayers. Strong light-trapping in the 3D PBG enables the long-lived polariton superfluid to be robust against fabrication-induced disorder and exciton line-broadening.