SPIN BALLISTIC TRANSPORT AND SPIN CURRENT OSCILLATIONS IN MESOSCOPIC LOOP STRUCTURES

Abstract

In the paper a theory of quantum interference in a loop structure caused by spin coherent transport and the Larmor precession of the electron spin is presented. The 'spin ballistic' regime is supposed to occur when the phase relaxation length of the spin part of electron wave function is much greater than the phase relaxation length of the 'orbital' part. If magnetic fields in two arms of the structure are different, the spin part of the wave function acquires a phase shift due to spin precession around the field. If the structure length L is chosen to be [Formula: see text], It is possible to 'wash out' the quantum interference related to the phase coherence of the 'orbital part' of the wave function, retaining at the same time that related to the phase coherence of the spin part and to reveal the corresponding conductance oscillations. Different mechanisms of spin relaxation as well as their influence on the spin transport are considered. The quantum interference in the time-dependent magnetic field is also discussed and similarities between this effect and Josephson one, as well as their differences are considered.