A valley degree of freedom (DOF) in transition metal dichalcogenides with broken inversion symmetry can be controlled through spin and orbital DOFs owing to their valley-contrasting characters. Another important aspect of the spin and orbital DOFs is that they affect quasiparticle scattering processes that govern the valley lifetime. Here we combine quasiparticle-interference (QPI) imaging experiments and theoretical simulations to study the roles of the spin and orbital DOFs in 3R-NbS2. We find that the QPI signal arising from an inter-valley scattering is noticeably weaker than that caused by an intra-valley scattering. We show that this behavior is predominantly associated with the orbital DOF, signifying the different spin and orbital structures of spin-split bands at each valley. These findings provide important insights into understanding the valley-related transport properties.
Cite
@article{arxiv.1708.01981,
title = {Orbital-dependent quasiparticle scattering interference in 3R-NbS2},
author = {T. Machida and Y. Kohsaka and R. Suzuki and M. Ochi and K. Iwaya and R. Arita and T. Hanaguri and Y. Iwasa},
journal= {arXiv preprint arXiv:1708.01981},
year = {2017}
}
Comments
12 pages, 6 figures, accepted for publication in PRB