Magnetoresistance in ferromagnetic metal/ferromagnetic semiconductor micro-structures

ORAL

Abstract

We use SQUID magnetometry and circular contacts to study the magnetoresistance in GaMnAs/Py bilayer structures. Our magnetization hysteresis loops show that there is no measurable coupling between the two ferromagnetic layers, even though they are not separated by any nano-magnetic spacer layers. Furthermore, the field-dependent magnetization shows a rich behavior that depends on the width of the GaMnAs in the circular structures. Samples with the narrowest gaps show a magnetoresistance effect that seems to be due to the tunneling magnetoresistance at the interface between py and GaMnAs.

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Authors

  • Taylor Reid

    Miami University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Oleg Popov

    Miami University, Chemistry Department, Penn State Univ., University Park, PA 16802, unaffiliated, Department of Materials Science and Engineering, Ohio State University Columbus, OH 43210, Department of Physics, Ohio State University, Columbus, OH 43210, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201, Korea Institute of Science and Technology, University of Cincinnati, Miami University of Ohio, University of Michigan, University of Notre Dame, University of Nebraska-Lincoln, Wayne State University, University of Tennessee, National Technical University of Athens, The University of Tennessee, Kettering Univeristy, University of Michigan-Dearborn, FNAL, Harvard University, California State University, Department of Physics, Kettering University, Flint, Michigan, Department of Natural Sciences, University of Michigan-Dearborn, Applied Sciences Inc., Cedarville, Ohio, Oakland University, University of Stockholm, Arizona State University

  • Khalid Eid

    Miami University