Effects of disorder on vortex gyration

ORAL

Abstract

The dynamics of magnetic domain wall structures driven by fields or currents is a subject of practical importance related to possible schemes for nanoscale magnetic memory devices. Experimental results are typically interpreted in comparison to ideal models that ignore the effects of extrinsic disorder and internal dynamics of domain wall structures. To understand the effect of disorder on the dynamics of vortex domain walls, we study the dynamics of vortex gyration driven by an external magnetic field pulse in the presence of extrinsic random potential. We analyze micromagnetic simulations using ideal models and observe that effective damping increases as the gyration frequency increases. We discuss the origin of the enhanced effective damping.

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Authors

  • Hongki Min

    Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899-6202, CNST, NIST, Gaithersburg, MD 20899 and NanoCenter, UMD, College Park, MD 20742

  • R.D. McMichael

    Center for Nanoscale Science and Technology, NIST, Gaithersburg, MD, USA, CNST NIST, Gaithersburg, MD 20899

  • J. Miltat

    Laboratoire de Physique des Solides Universite Paris XI Orsay, France

  • M.J. Donahue

    MCSD, NIST, Gaithersburg, MD 20899

  • M.D. Stiles

    Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899-6202, National Institute of Standards and Technology, Center for Nanoscale Science and Technology, National Institute of Standards and Technology, Gaithersburg, MD 20899, CNST, NIST, Gaithersburg, MD 20899