Valleytronics and pseudospintronics with chiral charge carriers in two-dimensional crystals

Electrons in two-dimensional atomic crystals such as few-layer sheets of graphene or transition-metal dichalcogenides carry several internal degrees of freedom: real spin, orbital pseudospin, and valley isospin. The interplay of these enables new approaches to spin-dependent transport effects. In this paper, three recent developments in this area are discussed: the unusual magnetoelectric properties of bilayer graphene, the possibility to generate valley-polarized currents in a vertical-tunneling heterostructure between single and bilayer sheets of graphene, and the spin response of single-layer transition-metal dichalcogenides.