Spin-dependent transmission through a mesoscopic ring: Determination of the spin-orbit interaction strengths from the final spin orientation and spin flips

摘要

The electronic, spin-dependent transmission through a ring is studied in the presence of the Rashba and Dresselhaus terms of the spin-orbit interaction (SOI), respectively, of strengths alpha and 0, and of a magnetic field B. We demonstrate a direct connection between alpha, beta, and the final spin orientations. For B = 0 the outgoing spins trace rings normal to the y (beta = 0), x (alpha = 0) axis. For beta = 0 (alpha = 0) incident spins polarized along the y (x) axis exit the ring parallel to the y (x) axis. The values of alpha and beta are extracted from the final spin orientation. For finite B this precession picture does not hold: spin flips occur when alpha (beta) is varied as the angles describing the spin orientation change drastically in a very narrow range of alpha (beta).