Exciton–polarons in two-dimensional semiconductors and the Tavis–Cummings model
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Date
2021-04Type
- Journal Article
ETH Bibliography
yes
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Abstract
The elementary optical excitations of a two-dimensional electron or hole system have been identified as exciton-Fermi-polarons. Nevertheless, the connection between the bound state of an exciton and an electron, termed trion, and exciton–polarons is subject of ongoing debate. Here, we use an analogy to the Tavis–Cummings model of quantum optics to show that an exciton–polaron can be understood as a hybrid quasiparticle—a coherent superposition of a bare exciton in an unperturbed Fermi sea and a bright collective excitation of many trions. The analogy is valid to the extent that the Chevy Ansatz provides a good description of dynamical screening of excitons and provided the Fermi energy is much smaller than the trion binding energy. We anticipate our results to bring new insight that could help to explain the striking differences between absorption and emission spectra of two-dimensional semiconductors Show more
Permanent link
https://doi.org/10.3929/ethz-b-000480998Publication status
publishedExternal links
Journal / series
Comptes Rendus. PhysiqueVolume
Pages / Article No.
Publisher
Académie des SciencesSubject
Exciton–polarons; Two-dimensional semiconductors; Tavis–Cummings model; Quantum optics; Many-body physicsOrganisational unit
03636 - Imamoglu, Atac / Imamoglu, Atac
Funding
178909 - Quantum photonics using van der Waals heterostructures (SNF)
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ETH Bibliography
yes
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