Related Experiment Video
Updated: Dec 27, 2025

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser
Published on: June 28, 2018
Strongly Surface State Carrier-Dependent Spin-Orbit Torque in Magnetic Topological Insulators
Xiaoyu Che1, Quanjun Pan1, Božo Vareskic1
1Department of Electrical and Computer Engineering, Department of Physics and Astronomy and Department of Materials Science and Engineering, University of California, Los Angeles, CA, 90095, USA.
Abstract:
The topological surface states (TSS) in topological insulators (TIs) can exert strong spin-orbit torque (SOT) on adjacent magnetization, offering great potential in implementing energy-efficient magnetic memory devices. However, there are large discrepancies among the reported spin Hall angle values in TIs, and its temperature dependence still remains elusive. Here, the spin Hall angle in a modulation-doped Cr-Bix Sb2- x Te3 (Cr-BST) film is quantitatively determined via both transport and optic approaches, where consistent results are obtained. A large spin Hall angle of ≈90 in the modulation-doped Cr-BST film is demonstrated at 2.5 K, and the spin Hall angle drastically decreases to 0.3-0.5 as the temperature increases. Moreover, by tuning the top TSS carrier concentration, a competition between the top and bottom TSS in contributing to SOT is observed. The above phenomena can account for the large discrepancies among the previously reported spin Hall angle values and reveal the unique role of TSS in generating SOT.
More Related Videos
Related Concept Videos
Atomic Nuclei: Nuclear Spin State Overview
Valence Bond Theory
Types Of Superconductors
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Atomic Nuclei: Nuclear Spin State Population Distribution
Atomic Nuclei: Nuclear Magnetic Moment

