Correlating EUV TMOKE and ARPES measurements to understand the temporal and spatial length scales underlying ultrafast demagnetization in nickel

ORAL

Abstract

Time-resolved magneto-optical Kerr effect spectroscopies spanning the M-shell absorption edges of magnetic materials provide powerful probes of the spin dynamics. However, to date, the disparate dynamics that occur at different depths in a laser-heated material were not disentangled. Here we show that this spatial averaging masks the true behavior of the material, where parts of the material at the surface can go through the ferromagnetic-paramagnetic phase transition, while deeper layers will not. We quantitatively compare depth sensitive time-resolved transverse magneto-optical Kerr effect measurements with time- and angle-resolved photoemission spectroscopy surface measurements on nickel. We show that the first critical behavior of the material occurs when the electron temperature as measured directly through ARPES and transient reflectivity reaches the Curie temperature, followed by a second critical behavior when the lattice temperature reaches the Curie temperature. These observations coupled with knowledge of the probing depth of each method, completely explain the results obtained from both experiments.

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Presenters

  • Phoebe Tengdin

    University of Colorado Boulder / JILA, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

Authors

  • Phoebe Tengdin

    University of Colorado Boulder / JILA, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Wenjing You

    JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Cong Chen

    JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Xun Shi

    Department of Physics and JILA, University of Colorado and NIST, Institute of Physics, Chinese Academy of Sciences, University of Colorado Boulder, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Dmitriy Zusin

    University of Colorado Boulder / JILA, JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Yingchao Zhang

    Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Christian Gentry

    University of Colorado Boulder / JILA, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Adam Blonsky

    University of Colorado Boulder / JILA, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Mark Keller

    National Institute of Standards and Technology, National Institute of Standards and Technology (NIST), NIST, NIST-Boulder

  • Peter Oppeneer

    Department of Physics and Astronomy, Uppsala University, Uppsala University

  • Henry Kapteyn

    Physics, Univ of Colorado - Boulder, Physics, University of Colorado Boulder, University of Colorado Boulder / JILA, JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Zhensheng Tao

    JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder

  • Margaret Murnane

    Physics, Univ of Colorado - Boulder, Physics, University of Colorado Boulder, University of Colorado Boulder / JILA, JILA, Department of Physics, University of Colorado Boulder and National Institute of Standards and Technology, Department of Physics and JILA, University of Colorado and NIST, Univ of Colorado - Boulder, Univ of Colorado-Boulder