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Negative-mass exciton polaritons induced by dissipative light-matter coupling in an atomically thin semiconductor.

ABSTRACT: Dispersion engineering is a powerful and versatile tool that can vary the speed of light signals and induce negative-mass effects in the dynamics of particles and quasiparticles. Here, we show that dissipative coupling between bound electron-hole pairs (excitons) and photons in an optical microcavity can lead to the formation of exciton polaritons with an inverted dispersion of the lower polariton branch and hence, a negative mass. We perform direct measurements of the anomalous dispersion in atomically thin (monolayer) WS₂ crystals embedded in planar microcavities and demonstrate that the propagation direction of the negative-mass polaritons is opposite to their momentum. Our study introduces the concept of non-Hermitian dispersion engineering for exciton polaritons and opens a pathway for realising new phases of quantum matter in a solid state.

SUBMITTER: Wurdack M

PROVIDER: S-EPMC9950362 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Negative-mass exciton polaritons induced by dissipative light-matter coupling in an atomically thin semiconductor.

Wurdack M M Yun T T Katzer M M Truscott A G AG Knorr A A Selig M M Ostrovskaya E A EA Estrecho E E

Nature communications 20230223 1

Dispersion engineering is a powerful and versatile tool that can vary the speed of light signals and induce negative-mass effects in the dynamics of particles and quasiparticles. Here, we show that dissipative coupling between bound electron-hole pairs (excitons) and photons in an optical microcavity can lead to the formation of exciton polaritons with an inverted dispersion of the lower polariton branch and hence, a negative mass. We perform direct measurements of the anomalous dispersion in at ...[more]

PMID: 36823076

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