Electric control of spin in monolayer WSe2 field effect transistors

摘要

We report first-principles theoretical investigations of quantum transport in a monolayer WSe2 field effect transistor (FET). Due to strong spin–orbit interaction (SOI) and the atomic structure of the two-dimensional lattice, monolayer WSe_2 has an electronic structure that exhibits Zeemanlike up–down spin texture near the K and K′ points of the Brillouin zone. In a FET, the gate electric field induces an extra, externally tunable SOI that re-orients the spins into a Rashba-like texture thereby realizing electric control of the spin. The conductance of FET is modulated by the spin texture, namely by if the spin orientation of the carrier after the gated channel region, matches or miss-matches that of the FET drain electrode. The carrier current I_(τ,s) in the FET is labelled by both the valley index and spin index, realizing valleytronics and spintronics in the same device.