Dr. Hao Wu
Songshan Lake Materials Laboratory, Guangdong, China
Reducing the energy consumption is one of the major challenges for next-generation spintronic devices. Spin-momentum locking in topological surface states gives rise to a giant spin-orbit torque (SOT) efficiency, and thus to reduce the writing energy of SOT devices. By combing the topological insulators (TIs) with in-plane magnetic tunnel junctions (MTJs), we demonstrate the proof-of-concept SOT-MRAM cell, where a large TMR ratio of 102% and the ultralow switching current density of 1.2 × 105 A cm−2 have been simultaneously achieved at room temperature. The charge-spin conversion efficiency θSH is characterized by the switching field shift and the spin-torque ferromagnetic resonance (ST-FMR) methods, and the >1 θSH proves the high efficiency of topological surface states. Moreover, the all-sputtered TI-MTJ device is demonstrated, showing the potential for wafer-scale industrial applications. Next, by combing the TIs with perpendicular MTJs, we realize the all-electrical low-power writing operation by combing the SOT with a small spin-transfer torque current, with the improving thermal stability and storage density. Our work proposes and demonstrates the magnetic memory driven by topological insulators, which may inspire the revolution of spintronic devices from classical to quantum materials.