Phase locking in a nonballistic multichannel spin field-effect transistor with an external magnetic field

Abstract

We study a multichannel spin field-effect transistor (SFET) in the presence of impurities and external magnetic fields, with special attention to the electronic coherence. Scattering by isotropic and spin-independent impurities is considered in the weakly diffusive regime. The conductance modulation of the SFET as a function of the Rashba spin-orbit coupling strength is numerically calculated via a recursive Green's function method using the tight-binding approximation of the Hamiltonian. We show that a scattering-induced phase-locking, reported previously [H.-W. Lee, S. Caliskan, and H. Park, Phys. Rev. B 72, 153305 (2005)] for a single-channel SFET, persists for a multichannel SFET.