Enhancing ground state population and macroscopic coherence of room-temperature WS$_2$ polaritons through engineered confinement

TL;DR

This study demonstrates engineered confinement in an all-dielectric microcavity that enhances ground state population and coherence of room-temperature WS$_2$ polaritons, advancing their potential for optoelectronic applications.

Contribution

The paper introduces a novel method to trap and enhance ground state occupancy and coherence of room-temperature polaritons in WS$_2$ monolayers through localized cavity modifications.

Findings

Enhanced polariton ground state population due to engineered confinement.

Significant suppression of disorder-induced dephasing.

Efficient optical transfer of polaritons into the trap.

Abstract

Exciton-polaritons (polaritons herein) in transition-metal dichalcogenide monolayers have attracted significant attention due to their potential for polariton-based optoelectronics. Many of the proposed applications rely on the ability to trap polaritons and to reach macroscopic occupation of their ground energy state. Here, we engineer a trap for room-temperature polaritons in an all-dielectric optical microcavity by locally increasing the interactions between the WS$_2$ excitons and cavity photons. The resulting confinement enhances the population and the first-order coherence of the polaritons in the ground state, with the latter effect related to dramatic suppression of disorder-induced inhomogeneous dephasing. We also demonstrate efficient population transfer into the trap when optically injecting free polaritons outside of its periphery.