Complete Spin and Valley Polarization by Total External Reflection from Potential Barriers in Bilayer Graphene and Monolayer Transition Metal Dichalcogenides

P. A. Maksym, H. Aoki

Published 2019-11-08Version 1

Transmission through potential barriers in bilayer graphene and transition metal dichalcogenides is shown to be valley asymmetric because of the low symmetry of the total Hamiltonian. In the total external reflection regime the transmission is 100% valley polarized in bilayer graphene and 100% spin and valley polarized in transition metal dichalcogenides, except for exponentially small corrections. The experimental requirements for using this effect to make valley and spin polarizers are described. Symmetry relations that may be useful for detecting valley polarization are given.