Spin-dependent Transport in GaAs/MnAs Core/shell Nanowires

ORAL

Abstract

Hybrid GaAs/MnAs core/shell nanowires synthesized by molecular beam epitaxy [APL {\bf 97}, 072505 (2010)] are of potential interest for proof-of-concept room temperature nanospintronics applications. Magnetic order in these nanostructures is directly influenced by a unique competition between the magnetocrystalline and shape anisotropies in MnAs. We report four probe measurements of the temperature dependence of the resistivity and the anisotropic magnetoresistance (AMR) in single nanowires over a temperature range 1 K - 300 K and in magnetic fields ranging up to 80 kOe, applied both parallel and perpendicular to the nanowire axis. We used the measured AMR in conjunction with micromagnetic simulations to reveal the detailed magnetization reversal process in the MnAs nanoshell. The micromagnetic simulations also provide insights into interesting structures for spin engineering at the nanoscale. Supported by NSF-MRSEC and ONR.

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Authors

  • Jing Liang

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • Jian Wang

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

  • A. Paul

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • B.J. Cooley

    Center for Nonlinear Dynamics and Department of Physics, University of Texas at Austin, Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • D.W. Rench

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • N.S. Dellas

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • S.E. Mohney

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • R. Engel-Herbert

    Center for Nanoscale Science and Materials Research Institute, Penn State University, University Park PA 16802

  • N. Samarth

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