Giant Hall Switching by Surface-State-Mediated Spin-Orbit Torque in a Hard Ferromagnetic Topological Insulator

Lixuan Tai, Haoran He, Su Kong Chong, Huairuo Zhang, Hanshen Huang, Gang Qiu, Yuxing Ren, Yaochen Li, Hung Yu Yang, Ting Hsun Yang, Xiang Dong, Bingqian Dai, Tao Qu, Qingyuan Shu, Quanjun Pan, Peng Zhang, Fei Xue, Jie Li, Albert V. Davydov, Kang L. Wang

Research output: Contribution to journalArticlepeer-review

Abstract

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)2Te3 (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 × 105Acm−2, 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) × 10−6TA−1cm2 and the interfacial charge-to-spin conversion efficiency to 3.9 ± 0.3 nm−1. The findings establish VBST as an extraordinary candidate for energy-efficient magnetic memory devices.

Original languageEnglish (US)
Article number2406772
JournalAdvanced Materials
Volume36
Issue number46
DOIs
StatePublished - Nov 14 2024
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2024 Wiley-VCH GmbH.

Keywords

  • current-induced switching
  • hard ferromagnets
  • magnetic topological insulators
  • spin-orbit torque
  • topological surface states

PubMed: MeSH publication types

  • Journal Article

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