Probing Bulk Electronic Structure with Hard X-ray Angle-Resolved Photoemission

ORAL

Abstract

Traditional ultraviolet and soft x-ray angle-resolved photoemission spectroscopy (ARPES) may in some cases be too strongly influenced by surface effects to be a useful probe of bulk electronic structure. Going to hard x-ray photon energies and thus larger electron inelastic mean-free paths should provide a more accurate picture of bulk electronic structure. I will present the first experimental data for hard x-ray ARPES (HARPES) at energies of 3.2 and 6.0 keV. The systems discussed are W, as a model transition-metal system to illustrate basic principles, and (Ga,Mn)As, as a technologically-relevant ferromagnetic semiconductor material to illustrate the potential broad applicability of this new technique. The experimental results are compared to free-electron final-state model calculations and more precise one-step photoemission theory including matrix element effects. Some likely future applications areas are discussed.

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Authors

  • Alexander Gray

    SLAC National Accelerator Laboratory, Menlo Park, CA, USA

  • Jan Minar

    Department of Chemistry, Ludwig Maximillian University, Munich, Germany

  • Shigenori Ueda

    NIMS Beamline Station at SPring-8, Hyogo, Japan

  • Juergen Braun

    Department of Chemistry, Ludwig Maximillian University, Munich, Germany

  • Hubert Ebert

    Department of Chemistry, Ludwig Maximillian University, Munich, Germany

  • Oscar Dubon

    Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA, USA

  • Keisuke Kobayashi

    NIMS Beamline Station at SPring-8, Hyogo, Japan

  • Charles Fadley

    Department of Physics, University of California Davis, Davis, CA, USA