Ultrafast transfer of magnetization on magnetic sublattices in half-metallic Co2MnGe heusler alloys

ORAL

Abstract

Heusler alloys are exciting materials for future applications because they display a wide range of tunable electronic and magnetic interactions such as metallicity, ferromagnetism, superconductivity, and giant magneto-resistance. However, laser-induced spin dynamics in heuslers were expected to be slower than in conventional metallic ferromagnets, due to the presence of a blocked spin channel. Here we directly observe ultrafast spin transfer from one magnetic sublattice to another in half-metallic heusler alloy Co2MnGe, that occurs on the timescale of the femtosecond laser excitation. Ultrafast high harmonic pulses make it possible to simultaneously record the element-specific magnetic dynamics of Co and Mn as the material undergoes demagnetization. The magnetization of Co is transiently enhanced by 10% within 60 fs, while that of Mn rapidly quenches. By comparing our data to density functional theory, we show that optical excitation can directly transfer spin from one magnetic sub-lattice to another, due to spin-polarized optical excitation pathways. The observed transient enhancement of ferromagnetic ordering demonstrates fast manipulation of spin by light, thus providing a path towards spintronics logic devices that can operate on femtosecond or even attosecond timescales.

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Presenters

  • Phoebe Tengdin

    • Physics, University of Colorado
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder / JILA
    • JILA, University of Colorado, Boulder

Authors

  • Phoebe Tengdin

    • Physics, University of Colorado
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder / JILA
    • JILA, University of Colorado, Boulder

  • Christian Gentry

    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder / JILA
    • JILA, University of Colorado, Boulder

  • Dmitriy Zusin

    • Physics, University of Colorado
    • JILA, University of Colorado Boulder
    • University of Colorado, Boulder / JILA
    • JILA, University of Colorado, Boulder

  • Adam Z Blonsky

    • JILA, University of Colorado Boulder
    • JILA, University of Colorado, Boulder

  • Justin Shaw

    • Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
    • National Institute of Standards and Technology Boulder
    • Quantum Electromagnetics Division, NIST, Boulder, CO, United States
    • National Institute of Standards and Technology, Boulder CO

  • Hans T. Nembach

    • Quantum Electromagnetics Division, National Institute of Standards and Technology, Boulder, Colorado 80305, USA
    • National Institute of Standards and Technology Boulder
    • JILA, University of Colorado, Boulder
    • Quantum Electromagnetics Division, NIST, Boulder, CO, United States
    • National Institute of Standards and Technology, Boulder CO

  • Monika Arora

    • National Institute of Standards and Technology, Boulder CO
    • National Institute of Standards and Technology Boulder

  • Thomas Silva

    • National Institute of Standards and Technology Boulder
    • NIST
    • Quantum Electromagnetics Division, NIST, Boulder, CO, United States
    • National Institute of Standards and Technology, Boulder CO

  • Yaroslav Kvashnin

    • Physics and Astronomy, Uppsala University
    • Uppsala University

  • Erna Delczeg

    • Uppsala University

  • Olle Eriksson

    • Uppsala University
    • Uppsala University and Örebro University
    • Physics and Astronomy, Uppsala University

  • Henry C Kapteyn

    • JILA, University of Colorado, Boulder
    • JILA, University of Colorado Boulder
    • Department of Physics and JILA, University of Colorado, Boulder
    • University of Colorado, Boulder / JILA
    • University of Colorado, Boulder

  • Margaret Mary Murnane

    • JILA, University of Colorado, Boulder
    • JILA, University of Colorado Boulder
    • Department of Physics and JILA, University of Colorado, Boulder
    • University of Colorado, Boulder / JILA
    • University of Colorado, Boulder