Tunable Dzyaloshinskii-Moriya Interaction in Ferrimagnetic GdCo alloy through Interface Engineering

ORAL

Abstract

Magnetic skyrmions are quasiparticles with potential applications in memory and logic devices. Controlling the interfacial Dzyaloshinskii-Moriya Interaction (DMI) plays a crucial role in manipulating skyrmion properties. We present a systematic analysis of the DMI variation in ferrimagnetic Pt/GdCo/Pt1-xWx multilayer as a function of Tungsten (W) composition (x) using Density Functional Theory (DFT). We find that ~10% W in the capping layer produces a non-zero DMI, and the DMI increases as the W composition increases but saturates at higher W composition in agreement with the experiment. We show that the vanishing of spin-orbit coupling (SOC) energy to the adjacent metal layers of the top interface and the simultaneous constancy of the bottom interface is responsible for such a saturating behavior of the DMI. Furthermore, we investigate Pt/GdCo/X (X = Ta, W, Ir) to demonstrate the impact of capping layer heavy metals on the DMI. We predict that W in the capping layer favors a higher DMI than Ta and Ir that shows a matching trend with the experimentally measured Spin Hall angle. Our results open up exciting combinatorial possibilities for controlling the DMI in ferrimagnets to nucleate and manipulate ultrasmall high-speed skyrmions.

*DARPA TEE program (grant D18AP00009)

–

Presenters

  • Md Golam Morshed

    • Univ of Virginia
    • Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, United States

Authors

  • Md Golam Morshed

    • Univ of Virginia
    • Department of Electrical and Computer Engineering, University of Virginia, Charlottesville, VA, United States

  • Khoong Hong Khoo

    • Institute of High Performance Computing
    • Institute of High Performance Computing, A*STAR
    • Institute of High Performance Computing, Agency for Science, Technology and Research
    • Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore, Singapore

  • Yassine Quessab

    • New York University
    • Center for Quantum Phenomena, Department of Physics, New York University, New York, NY, United States

  • Jun-Wen XU

    • Center for Quantum Phenomena, Department of Physics, New York University
    • Center for Quantum Phenomena, Department of Physics, New York University, New York, NY, United States

  • Robert Laskowski

    • Institute of High Performance Computing
    • Institute of High Performance Computing, Agency for Science, Technology and Research, Singapore, Singapore

  • Prasanna V Balachandran

    • Department of Materials Science and Engineering; Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, VA, United States

  • Andrew D Kent

    • Center for Quantum Phenomena, Department of Physics, New York University
    • Department of Physics, New York University
    • Center for Quantum Phenomena, Department of Physics, New York University, New York, NY, United States

  • Avik Ghosh

    • Univ of Virginia
    • Department of Electrical and Computer Engineering; Department of Physics, University of Virginia, Charlottesville, VA, United States