Ballistic spin resonance in multisubband quantum wires

Abstract

Ballistic spin resonance was experimentally observed in a quasi-one-dimensional wire by Frolov et al. [Nature (London) 458, 868 (2009)]. The spin resonance was generated by a combination of an external static magnetic field and the oscillating effective spin-orbit magnetic field due to periodic bouncings of the electrons off the boundaries of a narrow channel. An increase of the D'yakonov-Perel spin relaxation rate was observed when the frequency of the spin-orbit field matched that of the Larmor precession frequency around the external magnetic field. Here we develop a model to account for the D'yakonov-Perel mechanism in multisubband quantum wires with both the Rashba and Dresselhaus spin-orbit interactions. Considering elastic spin-conserving impurity scatterings in the time-evolution operator (Heisenberg representation), we extract the spin relaxation time by evaluating the time-dependent expectation value of the spin operators. The magnetic field dependence of the nonlocal voltage, which is related to the spin relaxation time behavior, shows a wide plateau, in agreement with the experimental observation. This plateau arises due to injection in higher subbands and small-angle scattering. In this quantum mechanical approach, the spin resonance occurs near the spin-orbit-induced energy anticrossings of the quantum wire subbands with opposite spins. We also predict anomalous dips in the spin relaxation time as a function of the magnetic field in systems with strong spin-orbit couplings.

Thermoelectric effects in graphene with local spin-orbit interaction

“…This type of interaction leads to band splittings and enriched spintronic effects [18,19]. In semiconductor quantum wires with parabolic confinement, the presence of localized Rashba interaction has been predicted to yield Fano antiresonances [20][21][22][23][24][25], to help the detection of entangled electrons [26][27][28], and to assist electron-spin resonance manipulation [29][30][31]. The effect of nonhomogeneous Rashba couplings has also been considered in the transport characteristics of two-dimensional systems [32][33][34][35][36].…”

Effects of interaction on field-induced resonances in a confined Fermi liquid

“…It reached a minimum for special values of the Zeeman splitting E Z . Quasi-classically, the dip in spin polarization was attributed to the commensuration between the spin precession time 2πE −1 Z (we henceforth set = 1) with twice the time it takes electrons to cross the channel in the direction of confinement, [16,17]. Hence the phenomenon was termed the Ballistic Spin Resonance (BSR).…”

Interplay between resonant tunneling and spin precession oscillations in all-electric all-semiconductor spin transistors

“…Spin injection and detection with QPCs have been discussed in Refs. [45,46] in the context of ballistic spin resonance. Here, we do not consider any external magnetic field and all the spin dynamics originates from the effective magnetic fields due to the spinorbit interactions present in the system, which makes our system an all-electric spin transistor.…”