Excitation of Chaotic Surface Spin Waves in Magnetic Film Feedback Rings through Three-Wave Processes

ORAL

Abstract

Surface spin waves in magnetic thin films can undergo three-wave splitting and confluence processes. In a splitting process, a surface spin wave produces two volume spin waves at about half of its frequency. In a confluence process, two half-frequency volume waves interact to produce a surface wave. This presentation reports the excitation of chaotic surface spin waves in magnetic thin film-based active feedback rings through these three-wave nonlinear interactions. Previous work has demonstrated such chaotic excitation in feedback rings. Neither the development of spectral modes nor the fractal dimensions of chaotic signals, however, have been reported. Experiments were performed with a 5 $\mu$m-thick yttrium iron garnet film and a static magnetic field of about 120 Oe. At some ring gain level, a single ring eigenmode was excited. As the gain was increased, one observed the excitation of additional modes, an increase in the frequency spacing between these modes, a period-doubling bifurcation, and the onset of chaos. One also observed a shift of the main mode to lower frequencies with increasing the gain. The correlation dimensions of the chaotic signals were found to be in the 2-4 range. It was also found that the correlation dimension increases with the ring gain.

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Authors

  • Aaron Hagersrom

    Department of Physics, Colorado State University

  • John Poate

    Brigham Young University, Los Alamos National Laboratory, Department of Physics and Astronomy, University of Utah, USA, MV Systems, Inc., USA, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Abteilung Silizium-Photovoltaik, Germany, Colorado School of Mines, Department of Physics, USA, Georgia Institute of Technology, Arizona State University, Physics Department of Babolsar University, Iran, Physics Department, New Mexico State University, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-1604, USA, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA, Department of Physics, Arizona State University, Tempe, AZ, 85287-1504, USA, Colorado State University, University of Wisconsin, NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, BYU-Provo, Michigan Technical University and Pierre Auger Collaboration, University of Colorado, Colorado School of Mines, Department of Physics, Colorado State University, Department of Physics, Cornell University, NASA, University of Massachusetts at Amherst, University of Massachusetss at Amherst, APS President, Harvard University, Society of Physics Students, Duke University, Computer Science, Brigham Young University, Chemistry \& Biochemistry, Brigham Young University, University of Arizona, University of Utah, Kansas State Univ., Bethel University, University of New Mexico, Stanford University, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, National Renewable Energy Laboratory, University of Denver, University of Colorado, Boulder, NREL, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287- 1604, USA, DU, ERI, Eleanor Roosevelt Institute (ERI), Cerro Tololo Interamerican Observatory, Utah State University, Center for Atmospheric and Space Sciences, Sciprint.org, University of Colorado at Boulder, JILA and University of Colorado, Kirchhoff Institute for Physics, University of Heidelberg, Utah Valley University, University of New South Wales, San Francisco State University, Weber State University, Cambridge University, Department of Physics and Astronomy, University of Utah, Kansas State University, Columbia University, NY, University of Colorado/JILA, Vice-President for Research and Technology Transfer, Colorado School of Mines

  • John Poate

    Brigham Young University, Los Alamos National Laboratory, Department of Physics and Astronomy, University of Utah, USA, MV Systems, Inc., USA, Helmholtz-Zentrum Berlin fuer Materialien und Energie, Abteilung Silizium-Photovoltaik, Germany, Colorado School of Mines, Department of Physics, USA, Georgia Institute of Technology, Arizona State University, Physics Department of Babolsar University, Iran, Physics Department, New Mexico State University, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287-1604, USA, Department of Electrical Engineering, University of Arkansas, Fayetteville, AR 72701, USA, Department of Physics, Arizona State University, Tempe, AZ, 85287-1504, USA, Colorado State University, University of Wisconsin, NSF ERC for Extreme Ultraviolet Science and Technology, Colorado State University, BYU-Provo, Michigan Technical University and Pierre Auger Collaboration, University of Colorado, Colorado School of Mines, Department of Physics, Colorado State University, Department of Physics, Cornell University, NASA, University of Massachusetts at Amherst, University of Massachusetss at Amherst, APS President, Harvard University, Society of Physics Students, Duke University, Computer Science, Brigham Young University, Chemistry \& Biochemistry, Brigham Young University, University of Arizona, University of Utah, Kansas State Univ., Bethel University, University of New Mexico, Stanford University, JILA, University of Colorado at Boulder, NIST, JILA, University of Colorado at Boulder, National Renewable Energy Laboratory, University of Denver, University of Colorado, Boulder, NREL, Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ, 85287- 1604, USA, DU, ERI, Eleanor Roosevelt Institute (ERI), Cerro Tololo Interamerican Observatory, Utah State University, Center for Atmospheric and Space Sciences, Sciprint.org, University of Colorado at Boulder, JILA and University of Colorado, Kirchhoff Institute for Physics, University of Heidelberg, Utah Valley University, University of New South Wales, San Francisco State University, Weber State University, Cambridge University, Department of Physics and Astronomy, University of Utah, Kansas State University, Columbia University, NY, University of Colorado/JILA, Vice-President for Research and Technology Transfer, Colorado School of Mines