Pulsed or Microwave Currents Induced Random Telegraph Signal in a Magnetic Tunnel Junction

ORAL

Abstract

Recent work has shown creation and dynamics of magnetic skyrmions, without the Dzyaloshinskii-Moriya interaction, in the free layer of a magnetic tunnel junction (MTJ) at a temperature of 4K [1]. In order to study how skyrmions, the topological excitations, can be protected against disorders and temperature fluctuations, we have extended our experimental investigation to higher temperatures, up to 200K, for various device sizes. For the intermediate resistance state, initiated by pulse or microwave currents, we have observed stochastic switching between two resistance states, commonly referred as the random telegraph signal (RTS). Statistics of the observed RTS depends on device temperature and microwave stimulation while the corresponding relations have been studied. In conjunction with micro-magnetic simulations, we discuss the interplay of the topological skyrmion and disorder-induced domains in MTJs.

[1] N. E. Penthorn, X. Hao, Z. Wang, Y. Huai, and H.W. Jiang, Experimental Observation of Single Skyrmion Signatures in a Magnetic Tunnel Junction, Phys. Rev. Lett., 122, 257201 (2019).

*The work was supported by National Science Foundation (NSF under Grant No. DMR-1809155).

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Presenters

  • Rajapaksayalage Rajapakse

    • Physics and Astronomy, University of California

Authors

  • Rajapaksayalage Rajapakse

    • Physics and Astronomy, University of California

  • Nicholas Penthorn

    • Physics and Astronomy, University of California
    • California State University, Los Angeles
    • University of California, Los Angeles

  • Xiaojie Hao

    • Avalanche Technology

  • Zihui Wang

    • Avalanche Technology

  • Yiming Huai

    • Avalanche Technology

  • HongWen Jiang

    • Physics and Astronomy, University of California
    • California State University, Los Angeles
    • University of California, Los Angeles