Controlled Rotation of Electrically Injected Spins in a Nonballistic Spin-Field-Effect Transistor.

Abstract

Electrically controlled rotation of spins in a semiconducting channel is a prerequisite for the successful realization of many spintronic devices, like, e.g., the spin-field-effect transistor (sFET). To date, there have been only a few reports on electrically controlled spin precession in sFET-like devices. These devices operate in the ballistic regime, as postulated in the original sFET proposal, and hence need high SOC channel materials in practice. Here, we demonstrate gate-controlled precession of spins in a nonballistic sFET using an array of narrow diffusive wires as a channel between a spin source and a spin drain. Our study shows that spins traveling in a semiconducting channel can be coherently rotated on a distance far exceeding the electrons' mean free path, and spin-transistor functionality can be thus achieved in nonballistic channels with relatively low SOC, relaxing two major constraints of the original sFET proposal.