Giant Hall Switching by Surface‐State‐Mediated Spin‐Orbit Torque in a Hard Ferromagnetic Topological Insulator
Topological insulators (TI) and magnetic topological insulators (MTI) can apply highly efficient spin-orbit torque (SOT) and manipulate the magnetization with their unique topological surface states (TSS) with ultrahigh efficiency. Here, efficient SOT switching of a hard MTI, V-doped (Bi,Sb)<sub>2</sub>Te<sub>3</sub> (VBST), with a large coercive field that can prevent the influence of an external magnetic field, is demonstrated. A giant switched anomalous Hall resistance of 9.2 kΩ is realized, among the largest of all SOT systems, which makes the Hall channel a good readout and eliminates the need to fabricate complicated magnetic tunnel junction (MTJ) structures. The SOT switching current density can be reduced to 2.8 × 10<sup>5 </sup>A<sup> </sup>cm<sup>-2</sup>, indicating its high efficiency. Moreover, as the Fermi level is moved away from the Dirac point by both gate and composition tuning, VBST exhibits a transition from edge-state-mediated to surface-state-mediated transport, thus enhancing the SOT effective field to (1.56 ± 0.12) × 10<sup>-6 </sup>T<sup> </sup>A<sup>-1 </sup>cm<sup>2</sup> and the interfacial charge-to-spin conversion efficiency to 3.9 ± 0.3 nm<sup>-1</sup>. The findings establish VBST as an extraordinary candidate for energy-efficient magnetic memory devices.
Authors
- Jie Li (ORCID: https://orcid.org/0000-0002-3733-4587)
- Fei Xue (ORCID: https://orcid.org/0000-0002-1737-2332)
- Lixuan Tai (ORCID: https://orcid.org/0000-0001-5144-7337)
- Tao Qu (ORCID: https://orcid.org/0000-0003-2455-6372)
- Qingyuan Shu (ORCID: https://orcid.org/0009-0009-2256-365X)
- Su Kong Chong (ORCID: https://orcid.org/0000-0002-2016-9802)
- Hanshen Huang (ORCID: https://orcid.org/0000-0003-1735-4473)
- Gang Qiu (ORCID: https://orcid.org/0000-0003-2248-3253)
- H. R. Zhang
- Quanjun Pan (ORCID: https://orcid.org/0000-0003-0633-9980)
- Bingqian Dai (ORCID: https://orcid.org/0000-0001-9904-4078)
- Hung‐Yu Yang (ORCID: https://orcid.org/0000-0002-4737-9826)
- Haoran He (ORCID: https://orcid.org/0000-0003-4282-2283)
- Albert V. Davydov (ORCID: https://orcid.org/0000-0003-4512-2311)
- Peng Zhang (ORCID: https://orcid.org/0000-0001-9309-7451)
- Xiang Dong (ORCID: https://orcid.org/0000-0002-5508-6011)
- Ting‐Hsun Yang
- Kang L. Wang (ORCID: https://orcid.org/0000-0002-9363-1279)
- Yuxing Ren
- Y. X. Li
Institutions
- Shanghai University (CN)
- National Institute of Standards and Technology (US)
- University of California, Los Angeles (US)
- University of Alabama at Birmingham (US)
- Theiss Research (US)
Publication Details
- Journal
- Advanced Materials
- Published
- 2024-09-23
- DOI
- https://doi.org/10.1002/adma.202406772
- Citations
- 13
- Primary Topic
- Magnetic properties of thin films
- Type
- article
- Field-Weighted Citation Impact
- 4.05
Funders
- National Science Foundation
- U.S. Department of Commerce
- National Natural Science Foundation of China
- Army Research Office