PT - JOURNAL ARTICLE AU - Li, Peng AU - Kally, James AU - Zhang, Steven S.-L. AU - Pillsbury, Timothy AU - Ding, Jinjun AU - Csaba, Gyorgy AU - Ding, Junjia AU - Jiang, J. S. AU - Liu, Yunzhi AU - Sinclair, Robert AU - Bi, Chong AU - DeMann, August AU - Rimal, Gaurab AU - Zhang, Wei AU - Field, Stuart B. AU - Tang, Jinke AU - Wang, Weigang AU - Heinonen, Olle G. AU - Novosad, Valentine AU - Hoffmann, Axel AU - Samarth, Nitin AU - Wu, Mingzhong TI - Magnetization switching using topological surface states AID - 10.1126/sciadv.aaw3415 DP - 2019 Aug 01 TA - Science Advances PG - eaaw3415 VI - 5 IP - 8 4099 - http://advances.sciencemag.org/content/5/8/eaaw3415.short 4100 - http://advances.sciencemag.org/content/5/8/eaaw3415.full SO - Sci Adv2019 Aug 01; 5 AB - 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.