Gate-Tunable Spin-to-Charge Conversion in Topological Insulator-Magnetic Insulator Heterostructures at Room Temperature

TL;DR

This study demonstrates that the spin Hall angle in topological insulator-magnetic insulator heterostructures can be significantly enhanced at room temperature through electrical gating, improving spin-to-charge conversion efficiency for spintronic applications.

Contribution

The paper introduces a method to tune the spin Hall angle in topological insulator films at room temperature using electrical gating, achieving high conversion efficiency.

Findings

Spin Hall angle reaches ~0.76 at room temperature.

Gating increases the spin Hall angle to ~0.9.

High-quality (Bi0.1Sb0.9)2Te3 films were synthesized.

Abstract

Over the past decade, topological insulators have received enormous attention for their potential in energy-efficient spin-to-charge conversion, enabled by strong spin-orbit coupling and spin-momentum locked surface states. Despite extensive research, the spin-to-charge conversion efficiency, usually characterized by the spin Hall angle ({\theta}SH), remains low at room temperature. In this work, we employed pulsed laser deposition to synthesize high-quality ternary topological insulators (Bi0.1Sb0.9)2Te3 thin films on magnetic insulator Y3Fe5O12. We find that the value of {\theta}SH reaches ~0.76 at room temperature and increases to ~0.9 as the Fermi level is tuned to cross topological surface states via electrical gating. Our findings provide an innovative approach to tailoring the spin-to-charge conversion in topological insulators and pave the way for their applications in energy-efficient spintronic devices.