A Multi-functional Spintronic Device Driven by Spin-orbit Interactions


We propose a simple two-terminal device that operates simultaneously as (i) a spin inverter for an incident polarized electron, (ii) a spin polarizer for an unpolarized source and (iii) a tunable spin current attenuator at certain range of electron energies. The device consists of a U-shaped nanowire with a uniform Dresselhaus spin-orbit coupling and a spatially-modulated Rashba spin-orbit coupling along the curved section. The latter is implemented through a tunable gate voltage at every alternating segment along the wire’s arc. This multi-purpose device does not need magnetic components or an external magnetic field to carry out the different functions as enumerated above. We discuss how the interplay of the wire’s geometry and the spin-orbit interaction present in the device drives its spin transport.