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DOE OSTI · 1802703

Magnetic domain dynamics in an insulating quantum ferromagnet

Silevitch, D. M.·Xu, J.·Tang, C.·Dahmen, K. A.·Rosenbaum, T. F.
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Abstract

The statistics and form of avalanches in a driven system reveal the nature of the underlying energy landscape and dynamics. In conventional metallic ferromagnets, eddy-current back action can dominate the dynamics. Here, we study Barkhausen noise in Li(Ho,Y)F 4 , an insulating Ising ferromagnet that cannot sustain eddy currents. In addition, for large avalanches at temperatures approaching the Curie point, we find a symmetric response free of drag effects. In the low-temperature limit, drag effects contribute to the dynamics, which we link to enhanced pinning from local random fields that are enabled by the microscopic dipole-coupled Hamiltonian (the Ising model in transverse field).

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Silevitch, D. M., Xu, J., Tang, C., Dahmen, K. A., Rosenbaum, T. F.. 2019-10-03. Magnetic domain dynamics in an insulating quantum ferromagnet. https://doi.org/10.1103/physrevb.100.134405

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