We propose and investigate a spin transistor device consisting of two ferromagnetic leads connected by a two-dimensional topological insulator as the channel material. It exploits the unique features of the topological spin-helical edge states, such that the injected carriers with a non-collinear spin-direction would travel through both edges and show interference effect. The conductance of the device can be controlled in a simple and allelectric manner by a side-gate voltage, which effectively rotates the spin-polarization of the carrier. At low voltages, the rotation angle is linear in the gate voltage, and the device can function as a good spin-polarization rotator by replacing the drain electrode with a paramagnetic material.
@article{arxiv.1510.06818,
title = {All-electric spin transistor based on a side-gate-modulated two-dimensional topological insulator},
author = {Xianbo Xiao and Ying Liu and Zhengfang Liu and Guoping Ai and Shengyuan A. Yang and Guanghui Zhou},
journal= {arXiv preprint arXiv:1510.06818},
year = {2016}
}