Modulation of spin dynamics in a channel of a non-ballistic spin field effect transistor

TL;DR

This paper models how gate voltage influences spin relaxation in a heterostructure, revealing a modest room-temperature spin polarization modulation of 15-20%, which is observable but not yet suitable for device use.

Contribution

The study develops a realistic model of spin dynamics in a non-ballistic spin FET channel, incorporating material parameters and gate voltage effects.

Findings

Spin polarization modulation of 15-20% at room temperature.

The effect is observable via optical pulse-probe techniques.

Modulation is insufficient for practical device applications.

Abstract

We have investigated the effect of the gate voltage on spin relaxation in an Al0.3Ga0.7As/GaAs/Al0.3Ga0.7As heterostructure. The study is motivated by a recent proposal for a non-ballistic spin field effect transistor that utilizes the interplay between the Rashba and the Dresselhaus spin-orbit interaction in the device channel. The model, which utilizes real material parameters, in order to calculate spin dynamics as a function of the gate voltage has been developed. From the obtained results we define the efficiency of the spin polarization and spin density modulation. The estimated modulation of the spin polarization at room temperature is of the order of 15-20%. The results show that the effect is not sufficient for device applications. However, it can be observed experimentally by optical pulse-probe techniques.