Unique Current-Direction-Dependent ON–OFF Switching in BiSbTeSe2 Topological Insulator-Based Spin Valve Transistors

In this letter, spin valve transistors are fabricated based on BiSbTeSe
₂
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 Ni
₂₁
Fe
₇₉
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.