Diffusion of spins in GaAs in the presence of a strongly spatially varying local magnetic field

ORAL

Abstract

We report on the effect of a localized, strongly inhomogeneous magnetic field on the behavior of spins in GaAs. Such magnetic fields can provide spatially resolved information regarding spin diffusion, relaxation and precession. The sample in our experiments is a 2 micron thick n-GaAs (3e16 cm$^{-3}$, Si doped) epitaxial membrane. A circularly polarized pump beam injects the spins into the membrane. The local magnetic field is provided by a micro-magnetic particle mounted on a commercial AFM cantilever. Spin-polarized photoluminescence is then used to measure the Hanle effect. The changes in the Hanle response as a function of the magnetic tip position provide information regarding the microscopic environment experienced by the spins. We also present numerical analysis of the spin diffusion equation for our experimental conditions.

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Authors

  • David Stroud

    Dept. of Physics, The Ohio State University

  • Vidya Bhallamudi

    Dept. of Electrical and Computer Engineering, The Ohio State University

  • Andrew Berger

    Dept. of Physics, The Ohio State University

  • Gang Xiang

    Dept. of Physics, The Ohio State University

  • Youngwoo Jung

    Dept. of Physics, The Ohio State University

  • Dominic Labanowski

    Dept. of Electrical and Computer Engineering, The Ohio State University

  • Denis Pelekhov

    The Ohio State University, The Ohio State University, Columbus OH, Dept. of Physics, The Ohio State University

  • Ezekiel Johnston-Halperin

    Department of Physics, The Ohio State University, Dept. of Physics, The Ohio State University, The Ohio State University

  • Mark Brenner

    Dept. of Electrical and Computer Engineering, The Ohio State University

  • Steven Ringel

    Dept. of Electrical and Computer Engineering, The Ohio State University

  • P. Chris Hammel

    The Ohio State University, Dept. of Physics, The Ohio State University