New findings could point the way to “valleytronics”
New findings from a team at MIT and other institutions could provide a pathway toward a kind of two-dimensional microchip that would make use of a characteristic of electrons other than their electrical charge, as in conventional electronics. The new approach is dubbed “valleytronics,” because it makes use of properties of an electron that can be depicted as a pair of deep valleys on a graph of their traits. The findings are described in a paper appearing in the journal Nature Materials, co-authored by MIT graduate student Edbert Jarvis Sie, MIT associate professor Nuh Gedik, and five others. The material the team studied is called tungsten disulfide (WS2), which belongs to a class of 2-D crystals known as transition metal dichalcogenides (TMDs). Like the single-layer carbon material called graphene, TMDs form thin films with a hexagonal, chicken-wire-like structure just a few atoms in thickness. (In the case of graphene, it is just...