Making sense of transport in WSe2

Physics Among materials that have a structure similar to that of graphene, but without a band gap, transition-metal dichalcogenides—such as MoS2 and WSe2—are the most prominent examples. Much of what we know about their electronic properties has come from optical measurements; the more traditional transport experiments have proven trickier. Fallahazad et al. studied the behavior of electrons in monolayers and bilayers of WSe2 subjected to an external magnetic field. As they tuned the field, the researchers observed characteristic oscillations in the transport properties. Analyses of these oscillations suggested that the electrons' spin and valley degrees of freedom were tightly coupled at lower fields, and only uncoupled at the highest applied fields of about 30 T. Phys. Rev. Lett. 116 , 086601 (2016).