1. Negative-mass exciton polaritons induced by dissipative light-matter coupling in an atomically thin semiconductor
- Author
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Wurdack, M., Yun, T., Katzer, M., Truscott, A. G., Knorr, A., Selig, M., Ostrovskaya, E. A., and Estrecho, E.
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - 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) WS$_2$ crystals embedded in planar microcavities and demonstrate that the propagation direction of the negative-mass polaritons is opposite to their momentum. Our study introduces a new concept of non-Hermitian dispersion engineering for exciton polaritons and opens a pathway for realising new phases of quantum matter in a solid state., Comment: 16 pages, 13 figures more...
- Published
- 2022
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