Room temperature skyrmions in layered magnet

ORAL

Abstract

The Néel-type skyrmion is usually observed at room temperature in multilayer metal films. Polar single-phase magnets, with broken symmetries of spatial inversion and time reversal, are expected to host Néel-type skyrmion. However, their skyrmionic state has been observed only at low temperatures. In this talk, we demonstrated the experimental observation of a Néel-type skyrmion lattice at room temperature in a layered 2D magnet, 50% Co-doped Fe5GeTe2 (FCGT) system. We studied the evolution of skyrmion at various magnetic fields, temperatures, thicknesses, and current in FCGT nanoflakes using Lorentz electron microscopy, variable-temperature magnetic force microscopy, and magneto-transport measurements. The skyrmion can be stabilized in 100~300 nm nanoflake at the temperature range from 260~340 K. The current-induced skyrmion motion was realized at room temperature, with a threshold current density ~ 2.1 ×106 A/cm-2. This discovery of skyrmions at room temperature in a non-centrosymmetric material opens the way for layered device applications.

 

*This work is supported by the Department of Defense, Air Force Office of Scientific Research under award FA9550-18-1-0480.and the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Materials Sciences and Engineering Division under contract DE-AC02-05CH11231 with the Quantum Materials program (KC2202).

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Presenters

  • Hongrui Zhang

    • University of California, Berkeley
    • UC Berkeley

Authors

  • Hongrui Zhang

    • University of California, Berkeley
    • UC Berkeley

  • Yu-Tsun Shao

    • Cornell University

  • Rui Chen

    • University of California, Berkeley
    • UC Berkeley

  • Xiang Chen

    • University of California at Berkeley
    • University of California, Berkeley
    • UC Berkeley

  • David Raftrey

    • University of California, Santa Cruz

  • Ying-Ting Chan

    • Rutgers University

  • Sandhya Susarla

    • Lawrence Berkeley National Lab
    • Lawrence Berkeley National Laboratory
    • Lawrence Berkeley National laboratory

  • Weida Wu

    • Rutgers University
    • Rutgers University, New Brunswick

  • Jie Yao

    • University of California, Berkeley
    • UC Berkeley

  • Peter Ercius

    • Berkeley National Laboratory
    • Lawrence Berkeley National Laboratory

  • Peter J Fischer

    • Lawrence Berkeley National Laboratory

  • David A Muller

    • Cornell University
    • School of Applied and Engineering Physics, Cornell University

  • Robert J Birgeneau

    • University of California, Berkeley

  • Ramamoorthy Ramesh

    • University of California, Berkeley