Spin transistor operation driven by the Rashba spin-orbit coupling in the gated nanowire

Abstract

The theoretical description has been proposed for the operation of the spin transistor in the gate-controlled InAs nanowire. The calculated current-voltage characteristics show that the current flowing from the source (spin injector) to the drain (spin detector) oscillates as a function of the gate voltage, which results from the precession of the electron spin caused by the Rashba spin-orbit interaction in the vicinity of the gate. We have studied two operation modes of the spin transistor: (A) the ideal operation mode with the full spin polarization of electrons in the contacts, the zero temperature, and the single conduction channel corresponding to the lowest-energy subband of the transverse motion and (B) the more realistic operation mode with the partial spin polarization of the electrons in the contacts, the room temperature, and the conduction via many transverse subbands taken into account. For mode (A) the spin-polarized current can be switched on/off by the suitable tuning of the gate voltage, for mode (B) the current also exhibits the pronounced oscillations but with no-zero minimal values. The computational results obtained for mode (B) have been compared with the recent experimental data and a good agreement has been found.

Interplay between Rashba interaction and electromagnetic field in the edge states of a two-dimensional topological insulator

“…and we shall assume that a Rashba interaction region, centered around the position x R and extending over a width W R , exists along such direction and can be described by the profile model (24). The total photoexcited electron density (44) consists of the two terms Eqs. (31) and (32) that, in the case of the Gaussian pulse (45), reduce to…”

“…This clearly appears when comparing the locations of the two counterpropagating partner wavepackets at t = 1 ps (dash-dotted green curves): while in the absence of Rashba interaction they would be located at symmetric positions x = ±0.5µm, the rightmoving one has been boosted by the Rahsba region further off from the origin, as compared to the left-moving one. (44)] is shown at various snapshots: t = 0.05 ps (thin solid curve), t = 0.5 ps (solid curve), t = 0.66 ps (dashed curve) and t = 1.0 ps (dash-dotted curve). Due to the increase of velocity (13) ascribed to the Rashba interaction, the right-moving wavepacket is "boosted" by the Rashba barrier, as compared to its left-moving photoexcited partner that does not impact the barrier.…”

Levitons in helical liquids with Rashba spin-orbit coupling probed by a superconducting contact

“…The effect of Rashba spin-orbit coupling, which breaks the conservation of spin axis in edge state [20,[78][79][80][81][82][83][84][85][86][87][88], can introduce additional scattering processes even within right-moving and left-moving channels. The presence of Rashba interaction in 2D TIs could be ascribed to an inversion asymmetry mechanism in the heterostructure or to strain effect [89][90][91][92][93][94], that could be induced, for instance, by an external electric field [95,96]. In this way, the splitting of Cooper pairs can occur within the same channel, without any breaking of time-reversal symmetry.…”

Spin filtering effect generated by the inter-subband spin-orbit coupling in the bilayer nanowire with the quantum point contact

“…The full explanation has been given by the further studies, which have shown that the predicted weak spin filter effect 17 can be strengthened by the electron-electron interaction leading to the nearly 100 % spin polarization in the regime of the single-mode transport 13 . QPCs with the SO interaction have been successfully used as the spin injector and detector in the recent experimental realization of the spin transistor 20,21 , in which about 10 5 times greater conductance oscillations have been observed as compared to the conventional spin-field effect transistor based on ferromagnets 22,23 .…”