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arXiv · 1708.08961

Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides

Kristen Kaasbjerg·Johannes H. J. Martiny·Tony Low·Antti-Pekka Jauho
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Abstract

Intervalley scattering by atomic defects in monolayer transition metal dichalcogenides (TDMs; MX2) presents a serious obstacle for applications exploiting their unique valley-contrasting properties. Here, we show that the symmetry of the atomic defects can give rise to an unconventional protection mechanism against intervalley scattering in monolayer TMDs. The predicted defect-dependent selection rules for intervalley scattering can be verified via Fourier transform scanning tunneling spectroscopy (FT-STS), and provide a unique identification of, e.g., atomic vacancy defects (M vs X). Our findings put the absence of the intervalley FT-STS peak in recent experiments in a different perspective.

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Kristen Kaasbjerg, Johannes H. J. Martiny, Tony Low, Antti-Pekka Jauho. 2018-01-03. Symmetry-forbidden intervalley scattering by atomic defects in monolayer transition-metal dichalcogenides. https://doi.org/10.1103/physrevb.96.241411

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