The Unique Current-Direction Dependent On-Off Switching in BiSbTeSe<sub>2</sub> Topological Insulator Based Spin Valve Transistors

Abstract

In this letter, spin valve transistors are fabricated based on BiSbTeSe2 topological insulator (TI) with enhanced surface mobility ( $\sim 4039$ cm $^{2}\text{V}^{-1}\text{s}^{-1})$ . The output in our spin valve transistors exhibits a dominant steplike behavior when sweeping the magnetic field to change the magnetization orientation of the Ni21Fe79 electrode. Most importantly, the ON (low resistance)–OFF (high resistance) state can be even switched when reversing the direction of the dc current. The TI-based spin valve transistors enable the current-direction-dependent switching of ON–OFF state, allowing for the applicability in magnetic sensors and spin-logic circuits, and show the potential use of TIs as innovative current-driven spin generators.