Conclusive Evidence for Impurity Band Conduction in Metallic Ga$_{1-x}$Mn$_{x}$As

ORAL

Abstract

The electronic structure and carrier dynamics of the dilute magnetic semiconductor Ga$_{1-x}$Mn$_{x}$As are studied via optical spectroscopy. We focus on the changes induced by annealing the samples, which is known to result in a large increase in the critical temperature. This study provides conclusive evidence that the Fermi energy ($E_{F}$) lies in a metallic impurity band.

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Authors

  • K.S. Burch

    • Los Alamos National Laboratory
    • MST-CINT, Los Alamos National Laboratory
    • MPA-CINT, Los Alamos National Laboratory

  • D.B. Shrekenhamer

    • Department of Physics, University of California, San Diego

  • E.J. Singley

    • Department of Physics, California State University, East Bay

  • J. Stephens

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara

  • B.L. Sheu

    • Department of Physics and Materials Research Institute, The Pennsylvania State University

  • R.K. Kawakami

    • Department of Physics, University of California, Riverside

  • D.D. Awschalom

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara

  • N. Samarth

    • Department of Physics and Materials Research Institute, The Pennsylvania State University

  • P. Schiffer

    • Department of Physics and Materials Research Institute, The Pennsylvania State University

  • D.N. Basov

    • Department of Physics, University of California, San Diego