Observation of thermal spin transfer torque via ferromagnetic resonance in magnetic tunnel junctions

ORAL

Abstract

The temperature gradient driven spin-transfer torque, called the thermal spin-transfer torque (TSTT) attracts people's attention since it has potential in magnetization switching by utilizing wasted heat as well as in the study of spin transportation. We observed the effects of TSTT on magnetic tunnel junction (MTJ) via analysis of the ferromagnetic resonance (FMR) spectra. We used an external laser beam to heat the MTJ in order to establish a temperature gradient effectively. A TSTT was driven by the temperature gradient and applied to the magnetization of the free FM layer of the MTJ. By measuring and analyzing the FMR spectra, after excluding the effects caused by the temperature rise, we conclude that the FMR line-shape change is a result of the TSTT generated by a temperature gradient via laser heating. The most interesting result is that the angular dependence of the TSTT and DC-bias spin-transfer torque are very different. A modified or new theory may be needed to explain this in the future.

*NSERC, CFI, URGP, CSC, Faculty of Graduate Studies of University of Manitoba, UMGSA, Faculty of Science of University of Manitoba

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Authors

  • Zhaohui Zhang

    • Department of Physics and Astronomy, University of Manitoba

  • Lihui Bai

    • Department of Physics and Astronomy, University of Manitoba
    • Department of Physics and Astronomy, University of Manitoba, Winnipeg, Canada R3T 2N2

  • Can-Ming Hu

    • Department of Physics and Astronomy, University of Manitoba

  • Xiaobin Chen

    • Centre for the Physics of Materials and Department of Physics, McGill University

  • Hong Guo

    • Centre for the Physics of Materials and Department of Physics, McGill University

  • Xiaolong Fan

    • Lanzhou University
    • The Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University

  • Desheng Xue

    • Lanzhou University
    • The Key Lab for Magnetism and Magnetic Materials of Ministry of Education, Lanzhou University
    • Key Laboratory for Magnetism and Magnetic materials of Ministry of Education, Lanzhou University, Lanzhou 730000, China

  • Dimitri Houssameddine

    • Everspin Technologies