Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA.
Center of Electron Microscopy and State Key Laboratory of Silicon Materials, School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China.
Nat Nanotechnol. 2016 Apr;11(4):352-9. doi: 10.1038/nnano.2015.294. Epub 2016 Jan 4.
Electric-field manipulation of magnetic order has proved of both fundamental and technological importance in spintronic devices. So far, electric-field control of ferromagnetism, magnetization and magnetic anisotropy has been explored in various magnetic materials, but the efficient electric-field control of spin-orbit torque (SOT) still remains elusive. Here, we report the effective electric-field control of a giant SOT in a Cr-doped topological insulator (TI) thin film using a top-gate field-effect transistor structure. The SOT strength can be modulated by a factor of four within the accessible gate voltage range, and it shows strong correlation with the spin-polarized surface current in the film. Furthermore, we demonstrate the magnetization switching by scanning gate voltage with constant current and in-plane magnetic field applied in the film. The effective electric-field control of SOT and the giant spin-torque efficiency in Cr-doped TI may lead to the development of energy-efficient gate-controlled spin-torque devices compatible with modern field-effect semiconductor technologies.
电场对磁有序的操控在自旋电子器件中具有重要的基础和技术意义。到目前为止，已经在各种磁性材料中探索了磁场、磁化和磁各向异性的电场控制，但自旋轨道扭矩（SOT）的有效电场控制仍然难以实现。在这里，我们报告了在使用顶栅场效应晶体管结构的 Cr 掺杂拓扑绝缘体（TI）薄膜中对巨大 SOT 的有效电场控制。在可访问的栅极电压范围内，SOT 强度可以调制四个因子，并且它与薄膜中的自旋极化表面电流具有很强的相关性。此外，我们证明了通过施加在薄膜中的恒流和平面磁场扫描栅极电压来实现磁化切换。Cr 掺杂 TI 中的 SOT 的有效电场控制和巨大的自旋扭矩效率可能会导致开发与现代场效应半导体技术兼容的节能栅控自旋扭矩器件。
