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)

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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.