Artificial Spin Ice in Exchange-biased Systems

ORAL  · Invited

Abstract

Exchange bias is used to fabricate a hybrid artificial spin ice composed of athermal Fe nanomagnets that are subject to site-specific unidirectional anisotropy, or a local magnetic field, applied in integer multiples of the lattice period along one sublattice of a classic square artificial spin ice (ASI). By varying this period and applying external fields, we demonstrate that the ground state is tunable in this hybrid ASI, and identify three distinct magnetic textures –– a striped ferromagnetic phase, an antiferromagnetic phase, and a state with magnetically charged pairs embedded in an antiferromagnetic matrix.  Monte Carlo simulations broadly support the ground state tunability of this hybrid ASI, and demonstrate that the pinning tunes relaxation timescales and their critical behavior.

*This work was supported by the National Science Foundation grant, NSF/DMR 1604186. Part of this work was conducted at the Washington Nanofabrication Facility / Molecular Analysis Facility, a National Nanotechnology Coordinated Infrastructure (NNCI) site at the University of Washington, which is supported in part by funds from the Molecular Engineering & Sciences Institute, the Clean Energy Institute, the Washington Research Foundation, the M. J. Murdock Charitable Trust, the National Science Foundation and the National Institutes of Health. G.M.M was supported by the Carnegie Trust for the Universities of Scotland, and the Universities of Glasgow and Manitoba. R.L.S. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC)—R.L.S. a été financé par le Conseil de recherches en sciences naturelles et en génie du Canada (CRSNG)

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Publication: Physical Review Letters 126, 017203 (2021)

Presenters

  • Kannan M Krishnan

    • University of Washington

Authors

  • Kannan M Krishnan

    • University of Washington

  • Vineeth M Parakkat

    • Cochin University of Science & Technology

  • Robert L Stamps

    • Univ of Manitoba

  • Gavin Macauley

    • University of Glasgow