Magnetic Field Effects on Spin Glass Dynamics

ORAL

Abstract

We have measured magnetic field effects on the dynamics of Cu0.89Mn0.11 thin film spin glasses of 20 nm thickness arranged in a multilayer structure. We extract the maximum free energy barrier height, Δmax , by allowing the perpendicular correlation length to reach the film thickness L. This fixes the correlated region in the spin glass, and results in activated dynamics with activation energy Δmax. The magnitude of Δmax is extracted by measuring the time dependence of the irreversible magnetization after the perpendicular correlation length has reached L. A new experimental protocol was invoked that accounts for the uncertainty in the time dependence of the field cooled magnetization. The change in the magnitude of Δmax with change in magnetic field generates the number of correlated spins. We find the correlated region to be of a pancake-like shape because of d = 2 dynamics after the perpendicular correlation length has reached L.

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Presenters

  • Qiang Zhai

    Physics, University of Texas, The University of Texas at Austin

Authors

  • Qiang Zhai

    Physics, University of Texas, The University of Texas at Austin

  • David Harrison

    Physics, University of Minnesota, School of Physics and Astronomy, University of Minnesota, University of Minnesota

  • Raymond Orbach

    Physics, University of Texas, Texas Materials Institute, The University of Texas at Austin, The University of Texas at Austin, Univ of Texas