Spin Blocker Using the Interband Rashba Effect in Symmetric Double Quantum Wells

Abstract

We propose a lateral spin-blockade devicethat uses the interbandRashba effect in a symmetric double quantum well (QW), where the Rashba effect in the conventional sense vanishes because of its inversion symmetry. The interband Rashba effect manifests itself in the off-diagonal term (represented by the parameter η) in the QW space using the bonding and antibonding basis [Esmerindo Bernardes, John Schliemann, Minchul Lee, J. Carlos Egues, and Daniel Loss, Phys. Rev. Lett. 99, 076603 (2007)]. In such a system, spin selection is possible by tuning the device length, gate electric field and in-plane magnetic field. We particularly show illustrative mechanisms using a one-dimensional model with k ¼ ðk F ; 0Þ, where the selected spin can be blocked completely in the presence of the in-plane magnetic field. While the inclusion of the finite k y and/or the gate electric field deteriorates the spin polarization P, finite values remain for P (P > 11%). Our proposal can also be regarded as an effective way of enhancing a variation of the Rashba-Edelstein effect, the generation of bulk spin polarization by electric current, based on semiconductor band engineering technology.

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

“…Furthermore, it yieds Fano lineshapes [52] that dramatically alter the conductance curves [48,[52][53][54][55]. We note that there exists another type of intersubband spin orbit coupling potential that occurs in coupled wells with two subbands [56]. Here, we consider the case of an intense confinement in the growth direction such that only the lowest subband is populated.…”

D'yakonov-Perel' spin relaxation in a bilayer with local structural inversion asymmetry

“…Among systems with locally broken inversion symmetry, we consider a symmetric double-quantum-well structure (DQWS) [16,[19][20][21][22][23][24][25][26][27][28] (illustrated in Fig. 1) in which electronic states can be controlled by changing the composition and the width of the well and barrier layers and by varying the potential with use of the applied electric field and the doping.…”

Spin drift and diffusion in one- and two-subband helical systems

“…Tuning the spin-orbit couplings (SOCs) in a twodimensional electron gas (2DEG) due to structural (Rashba) and bulk (Dresselhaus) inversion asymmetry is an intensely studied method for the coherent control of spin dynamics, which is the motivation [10] and one of the central goals of spintronics research [11][12][13][14]. Since the initial proposal of the ballistic spin transistor [10], generalizations have been developed to make it robust against spin-independent scattering [8,[15][16][17], in order to preserve the spin at a certain orientation.…”