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arXiv · 1709.02159

Room temperature magnetization switching in topological insulator-ferromagnet heterostructures by spin-orbit torques

Yi Wang·Dapeng Zhu·Yang Wu·Yumeng Yang·Jiawei Yu·Rajagopalan Ramaswamy·Rahul Mishra·Shuyuan Shi·Mehrdad Elyasi·Kie-Leong Teo·Yihong Wu·Hyunsoo Yang
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Abstract

Topological insulators (TIs) with spin momentum locked topological surface states (TSS) are expected to exhibit a giant spin-orbit torque (SOT) in the TI/ferromagnet systems. To date, the TI SOT driven magnetization switching is solely reported in a Cr doped TI at 1.9 K. Here, we directly show giant SOT driven magnetization switching in a Bi2Se3/NiFe heterostructure at room temperature captured using a magneto-optic Kerr effect microscope. We identify a large charge to spin conversion efficiency of ~1-1.75 in the thin TI films, where the TSS is dominant. In addition, we find the current density required for the magnetization switching is extremely low, ~6x10^5 A cm-2, which is one to two orders of magnitude smaller than that with heavy metals. Our demonstration of room temperature magnetization switching of a conventional 3d ferromagnet using Bi2Se3 may lead to potential innovations in TI based spintronic applications.

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Yi Wang, Dapeng Zhu, Yang Wu, Yumeng Yang, Jiawei Yu, Rajagopalan Ramaswamy, Rahul Mishra, Shuyuan Shi, Mehrdad Elyasi, Kie-Leong Teo, Yihong Wu, Hyunsoo Yang. 2017-09-07. Room temperature magnetization switching in topological insulator-ferromagnet heterostructures by spin-orbit torques. https://doi.org/10.1038/s41467-017-01583-4

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