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arXiv · 1711.02713

Orbital symmetry and the optical response of single-layer monochalcogenides

Gabriel Antonius·Diana Y. Qiu·Steven G. Louie
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Abstract

The absorption spectra of single-layer GaSe and GaTe in the hexagonal phase feature exciton peaks with distinct polarization selectivity. We investigate these distinct features from first-principle calculations using the GW-BSE formalisms. We show that the brightness of the exciton absorption peaks is tunable with the polarization of the light. Due to the symmetry of the bands under z-axis mirror symmetry, the bound exciton states selectively couple to either in-plane or out-of-plane polarization of the light. In particular, for a p-polarized light absorption experiment, the absorption peaks of the s-like excitons emerge at large angle of incidence, while the overall absorbance reduces over the rest of the spectrum.

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Gabriel Antonius, Diana Y. Qiu, Steven G. Louie. 2018-05-09. Orbital symmetry and the optical response of single-layer monochalcogenides. https://doi.org/10.1021/acs.nanolett.7b05286

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