Electron dephasing and decoherence of neutral donor bound electrons in GaAs

ORAL

Abstract

Strong oscillator strengths, small inhomogeneous broadenings of the optical transitions, and semiconductor device integration possibilities make the GaAs donor-bound exciton (D0X) system an attractive candidate for electromagnetically induced transparency based applications. However, the recent observation of coherent population trapping in the GaAs D0X system indicates a fast (1-2 ns) dephasing rate of the bound- electron spin states which severely limits the achievable transparency. Theoretical and experimental research in other groups indicate the fast dephasing is due to the random nuclear spin environment in the GaAs lattice. We perform measurements of the electron Zeeman Raman transition linewidth which confirm the 1-2 ns dephasing rate. Using this technique, we study the effect of doping density and magnetic field on the Raman linewidth. Both variables can theoretically affect the inhomogeneous broadening due to the nuclear spin environment. If the inhomogeneous broadening can be decreased, spin-echo techniques should be possible to further increase the spin dephasing time to the homogeneous microsecond regime.

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Authors

  • Kai-Mei Fu

  • Susan Clark

    Stanford University

  • Charles Santori

    Hewlett-Packard Laboratories

  • Bingyang Zhang

    Stanford University

  • Colin Stanley

  • Jinho Lee

    University of Glasgow, Chief Scientist, BP, JILA, NIST and University of Colorado, Boulder, Department of Physics, Brown University, Instituto Nacional de Pesquisas Espaciais, Sao Jose dos Campos, SP Brazil, Laboratory of Physics, Helsinki University of Technology, Oakland University, Helsinki University of Technology, Cornell University, University of Tokyo, Japan, Los Alamos National Laboratory, Lawrence Berkeley Laboratory

  • Yoshihisa Yamamoto

    Stanford University