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DOE OSTI · 1783788

Optically Probing Tunable Band Topology in Atomic Monolayers

Xu, Gaofeng·Zhou, Tong·Scharf, Benedikt·Žutić, Igor
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Abstract

In many atomically thin materials, their optical absorption is dominated by excitonic transitions. It was recently found that optical selection rules in these materials are influenced by the band topology near the valleys. We propose that gate-controlled band ordering in a single atomic monolayer, through changes in the valley winding number and excitonic transitions, can be probed in helicity-resolved absorption and photoluminescence. Here, this predicted tunable band topology is confirmed by combining an effective Hamiltonian and a Bethe-Salpeter equation for an accurate description of excitons, with first-principles calculations suggesting its realization in Sb-based monolayers.

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2-dimensional systems75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITYApproximation methods for many-body systemsExcitonsFirst-principles calculationsMonolayer filmsOptoelectronicsTopological phases of matter

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Xu, Gaofeng, Zhou, Tong, Scharf, Benedikt, Žutić, Igor. 2020-10-08. Optically Probing Tunable Band Topology in Atomic Monolayers. https://doi.org/10.1103/physrevlett.125.157402

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