Magnetic memory driven by topological insulators

Hao Wu; Aitian Chen; Peng Zhang; Haoran He; John Nance; Chenyang Guo; Julian Sasaki; Takanori Shirokura; Pham Nam Hai; Bin Fang; Seyed Armin Razavi; Kin Wong; Yan Wen; Yinchang Ma; Guoqiang Yu; Gregory P Carman; Xiufeng Han; Xixiang Zhang; Kang L Wang

doi:10.1038/s41467-021-26478-3

Magnetic memory driven by topological insulators

Nat Commun. 2021 Oct 29;12(1):6251. doi: 10.1038/s41467-021-26478-3.

Authors

Hao Wu^#¹, Aitian Chen^#², Peng Zhang^#³, Haoran He³, John Nance⁴, Chenyang Guo⁵, Julian Sasaki⁶, Takanori Shirokura⁶, Pham Nam Hai^{6

7}, Bin Fang², Seyed Armin Razavi³, Kin Wong³, Yan Wen², Yinchang Ma², Guoqiang Yu⁵, Gregory P Carman⁴, Xiufeng Han⁵, Xixiang Zhang², Kang L Wang⁸

Affiliations

¹ Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA. [email protected].
² Physical Science and Engineering Division, King Abdullah University of Science and Technology, Thuwal, 23955-6900, Saudi Arabia.
³ Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA.
⁴ Department of Mechanical and Aerospace Engineering, University of California, Los Angeles, CA, 90095, USA.
⁵ Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, China.
⁶ Department of Electrical and Electronic Engineering, Tokyo Institute of Technology, Tokyo, 152-8550, Japan.
⁷ Center for Spintronics Research Network (CSRN), The University of Tokyo, Tokyo, 113-8656, Japan.
⁸ Department of Electrical and Computer Engineering, and Department of Physics and Astronomy, University of California, Los Angeles, CA, 90095, USA. [email protected].

^# Contributed equally.

Abstract

Giant spin-orbit torque (SOT) from topological insulators (TIs) provides an energy efficient writing method for magnetic memory, which, however, is still premature for practical applications due to the challenge of the integration with magnetic tunnel junctions (MTJs). Here, we demonstrate a functional TI-MTJ device that could become the core element of the future energy-efficient spintronic devices, such as SOT-based magnetic random-access memory (SOT-MRAM). The state-of-the-art tunneling magnetoresistance (TMR) ratio of 102% and the ultralow switching current density of 1.2 × 10⁵ A cm^-2 have been simultaneously achieved in the TI-MTJ device at room temperature, laying down the foundation for TI-driven SOT-MRAM. The charge-spin conversion efficiency θ_SH in TIs is quantified by both the SOT-induced shift of the magnetic switching field (θ_SH = 1.59) and the SOT-induced ferromagnetic resonance (ST-FMR) (θ_SH = 1.02), which is one order of magnitude larger than that in conventional heavy metals. These results inspire a revolution of SOT-MRAM from classical to quantum materials, with great potential to further reduce the energy consumption.

Abstract

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