Spin Control of Drifting Electrons using Local Nuclear Polarization in Ferromagnet-Semiconductor Heterostructures

ORAL

Abstract

We demonstrate a spatially-confined magnetic field gate to modulate the Larmor frequency of an optically-injected spin ensemble drifting down a GaAs channel [1]. The gate is activated either optically or electrically and polarizes GaAs nuclear spins at the interface between a lithographically-defined MnAs island and the channel via the ferromagnetic proximity polarization effect. We measure the rotation angle of the spin ensemble as it emerges from the polarized region using time-resolved Kerr rotation. The ensemble's spin rotation angle can be tuned by up to 5$\pi$ radians as the spins travel over 30 $\mu $m by controlling the nuclear field strength and adjusting the drift velocity. \\[4pt] [1] M.E. Nowakowski, et. al., Phys. Rev. Lett. 105, 137206 (2010)

*Work supported by ONR and NSF.

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Authors

  • M.E. Nowakowski

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106

  • Gregory Fuchs

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106
    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA
    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara

  • Shawn Mack

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106
    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara

  • D.D. Awschalom

    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA 93106
    • University of California, Santa Barbara
    • University of California Santa Barbara
    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara, CA
    • Center for Spintronics and Quantum Computation, University of California, Santa Barbara
    • Physics Dept., University of California, Santa Barbara CA 93106

  • N. Samarth

    • Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, PA 16802
    • Physics Dept., Penn State University, University Park PA 16802
    • Pennsylvania State University
    • Department of Physics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA
    • Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802.