Engineering the interlayer exchange coupling in hybrid ferromagnetic metal/semiconductor heterostructures

ORAL

Abstract

The systematic engineering of exchange coupling in ferromagnetic semiconductor heterostructures is important for developing proof-of-concept spin transfer semiconductor devices. We recently demonstrated interlayer exchange coupling between a ferromagnetic semiconductor (Ga$_{1-x}$Mn$_x$As) and a ferromagnetic metal (MnAs) [APL {\bf 91}, 192503 (2007)]. Here, we report a comprehensive magnetometry study of the underlying exchange coupling in this hybrid system. We vary key parameters such as the thicknesses of both the ferromagnetic layers and the composition of the Ga$_{1-x}$Mn$_x$As layer, and explain our observations using an ``exchange spring'' model. We also demonstrate the propagation of the exchange coupling through a non-magnetic spacer layer (p-doped GaAs) and examine the variation of this coupling as a function of the spacer layer thickness and doping. Work supported by the ONR MURI program and by NSF.

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Authors

  • Mark J. Wilson

    Dept. of Physics, Penn State University, University Park PA 16802

  • Meng Zhu

    Dept. of Physics, Penn State University, University Park PA 16802, NIST, Gaithersburg, MD, 20899 / University of Maryland, College Park, MD, 20742

  • Peter Schiffer

    Dept. of Physics, Penn State University, University Park PA 16802

  • Nitin Samarth

    Materials Research Institute, Penn State University., The Pennsylvania State University, Penn State University, Dept. of Physics, Penn State University, University Park PA 16802

  • Roberto Myers

    Ohio State University, Dept. of Physics, University of California, Santa Barbara CA 93106

  • D.D. Awschalom

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

  • M. E. Flatt\'e

    Department of Physics and Astronomy, University of Iowa, Optical Science and Technology Center and Department of Physics and Astronomy, University of Iowa, Dept. of Physics, University of Iowa., University of Iowa, Department of Physics and Astronomy University of Iowa, OSTC and Department of Physics and Astronomy, University of Iowa, Dept. of Physics, University of Iowa, Iowa City, IA 52242