Time-Resolved Quadratic Magneto-Optical Kerr Effect for Studies of In-plane Magnetic Dynamics

ORAL

Abstract

We present an approach for the measurement of in-plane magnetic dynamics with time-resolved quadratic magneto-optical Kerr effect (TR-QMOKE). Because the QMOKE signal is proportional to the square of the magnetic moment, TR-QMOKE can be applied to both ferromagnetic and antiferromagnetic materials with in-plane magnetic moment (e.g., Mn2As, Mn3B4). The measurement is done with an ultrafast laser based pump-probe system, in which the dynamics of the second order term of dielectric constant is measured. We measured the demagnetization of Co thin film with in-plane anisotropy with perpendicularly incident laser beam. The transient rotation signal is on the order of a few micro-radians, approximately an order of magnitude smaller than the transient polar MOKE signal of a CoPt multilayer with perpendicular anisotropy. We extract the demagnetization signal by separating the precession contribution to the polarization-dependent raw data using semi-phenomenological fitting.

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Presenters

  • Kexin Yang

    Physics Department, University of Illinois at Urbana-Champaign

Authors

  • Kexin Yang

    Physics Department, University of Illinois at Urbana-Champaign

  • Arun Ramanathan

    Los Alamos National Lab

  • Jingwen Yu

    Materials Science and Engineering, University of Illinois at Urbana-Champaign

  • Daniel Shoemaker

    Materials Science and Engineering, University of Illinois at Urbana-Champaign, Materials Science and Engineering and Frederick Seitz Materials Research Laboratory, University of Illinois Urbana Champaign

  • David Cahill

    Materials Science and Engineering, University of Illinois at Urbana-Champaign, Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, University of Illinois at Urbana-Campaign, University of Illinois at Urbana-Champaign, University of Illinois at Urbana–Champaign, Department of Materials Science and Engineering and Materials Research Laboratory, Univ of Illinois - Urbana, Univ of Illinois - Urbana, Univ of Illinois at Urbana-Champaign, Department of Materials Science and Engineering, University of Illinois