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

Kristen Kaasbjerg, Johannes H. J. Martiny, Tony Low, Antti-Pekka Jauho
2017 Physical review B  
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
more » ... py (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.
doi:10.1103/physrevb.96.241411 fatcat:2t3tu3mfojejxhgqxcrnd6bfwe