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

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 (θ_SH), remains relatively low at room temperature. In this work, pulsed laser deposition is employed to fabricate high-quality ternary topological insulator (Bi_0.1Sb_0.9)₂Te₃ thin films on magnetic insulator Y₃Fe₅O₁₂. It is found that the value of θ_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. These 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.