Magnetization switching using topological surface states

Peng Li, James Kally, Steven S.L. Zhang, Timothy Pillsbury, Jinjun Ding, Gyorgy Csaba, Junjia Ding, J. S. Jiang, Yunzhi Liu, Robert Sinclair, Chong Bi, August DeMann, Gaurab Rimal, Wei Zhang, Stuart B. Field, Jinke Tang, Weigang Wang, Olle G. Heinonen, Valentine Novosad, Axel HoffmannNitin Samarth, Mingzhong Wu

Research output: Contribution to journalArticlepeer-review

67 Scopus citations

Abstract

Topological surface states (TSSs) in a topological insulator are expected to be able to produce a spin-orbit torque that can switch a neighboring ferromagnet. This effect may be absent if the ferromagnet is conductive because it can completely suppress the TSSs, but it should be present if the ferromagnet is insulating. This study reports TSS-induced switching in a bilayer consisting of a topological insulator Bi2Se3 and an insulating ferromagnet BaFe12O19. A charge current in Bi2Se3 can switch the magnetization in BaFe12O19 up and down. When the magnetization is switched by a field, a current in Bi2Se3 can reduce the switching field by ~4000 Oe. The switching efficiency at 3 K is 300 times higher than at room temperature; it is ~30 times higher than in Pt/BaFe12O19. These strong effects originate from the presence of more pronounced TSSs at low temperatures due to enhanced surface conductivity and reduced bulk conductivity.

Original languageEnglish (US)
Article numbereaaw3415
JournalScience Advances
Volume5
Issue number8
DOIs
StatePublished - Aug 30 2019

ASJC Scopus subject areas

  • General

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