Enhancement of spin-wave propagation using topological insulators

ORAL

Abstract

Spin-wave damping in planar Yttrium Iron Garnet (YIG) films remains the main drawback in integrating ferromagnetic films with Radio Frequency Integrated Circuits. Most studies have often used Pt as a source of spin current through the spin Hall effect to provide an anti-damping torque. Apart from Pt and other heavy metals, another class of materials that can also be used are topological insulators (TI) where the current at the surface is spin polarized. Therefore, YIG/TI has great potential to enhance spin-wave propagation in ferromagnetic materials.
Here, we present the first study of spin-wave amplification in LPE YIG/TI. We used a 15 nm thick Bi2Se3 as the TI layer, which was grown by molecular beam epitaxy on a 3 μm thick YIG layer. We measured the change in spin-wave amplitude as the current in the TI layer was varied. We used the critical current density as our figure of merit which is the current density required to entirely suppress spin-wave damping. We show that this current is three times smaller than that in YIG/Pt which means TI is a more efficient material for spin-wave amplification.

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Presenters

  • Aryan Navabi

    • Univ of California - Los Angeles

Authors

  • Aryan Navabi

    • Univ of California - Los Angeles

  • Yuxiang Liu

    • Univ of California - Los Angeles
    • Electrical Engineering, University of California Los Angeles

  • Pramey Upadhyaya

    • Univ of California - Los Angeles

  • Farbod Ebrahimi

    • Inston Inc.

  • Guoqiang Yu

    • University of California, Los Angeles
    • Univ of California - Los Angeles
    • Department of Electrical Engineering, UCLA
    • BeiHang University
    • Electrical Engineering, University of California Los Angeles

  • Koichi Murata

    • Univ of California - Los Angeles
    • Electrical Engineering, UCLA

  • Lei Pan

    • Univ of California - Los Angeles
    • Department of Electrical Engineering, University of California, Los Angeles
    • University of California Los Angeles
    • UCLA
    • Electrical Engineering, UCLA

  • Pedram Khalili Amiri

    • Northwestern University

  • Yaroslav Tserkovnyak

    • University of California - Los Angeles

  • Kang Wang

    • University of California, Los Angeles
    • Univ of California - Los Angeles
    • Department of Electrical Engineering, University of California, Los Angeles
    • Department of Electrical Engineering, UCLA
    • University of California Los Angeles
    • UCLA
    • Department of Electrical Engineering, Univ of California - Los Angeles
    • Electrical and Computer Engineering, University of California, Los Angeles
    • Electrical Engineering, UCLA