A valley valve and electron beam splitter

Abstract

Making a practical valleytronics device Two-dimensional materials with a hexagonal lattice, such as graphene, have two distinct “valleys” in their band structure. Researchers in the emerging field of valleytronics hope that these valley degrees of freedom can be exploited as information carriers, but making valleytronic devices is tricky. Li et al. created chiral valley Hall states on the boundary between oppositely gated regions of bilayer graphene. They then guided these so-called kink states through their sample using spatially modulated gating, demonstrating right and left turns, as well as a valley valve function. Science , this issue p. 1149