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Microwave Radiation from YIG Magnons

Research Project

Project/Area Number 09640435
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field 固体物性Ⅱ(磁性・金属・低温)
Research InstitutionOKAYAMA UNIVERSITY

Principal Investigator

YAMAZAKI Hitoshi  Okayama University, Faculty of Science Professor, 理学部, 教授 (40013495)

Co-Investigator(Kenkyū-buntansha) MINO Michinobu  Okayama University, Faculty of Science Research Associate, 理学部, 助手 (30222326)
Project Period (FY) 1997 – 1998
Project Status Completed (Fiscal Year 1998)
Budget Amount *help
¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 1998: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1997: ¥3,300,000 (Direct Cost: ¥3,300,000)
KeywordsMAGNON / SPIN-WAVE / PARALLEL PUMPING / MICROWAVE RADIATION / YIG / PARAMETRIC EXCITATION
Research Abstract

Unstable growth of particular magnon can be generated by nonlinear excitation (parametric excitation) with high microwave power. Those magnons in the nonequilibrium state are scattered to other magnons, which have different frequencies and wave_ vectors. Those magnons occasionally radiate microwave. Magnon interactions or magnon condensation state can be studied by detecting microwave radiation from the nonequilibrium magnon system.
Nonequilibrium magnons excited in a single crystal of ferrimagnet YIG (Yttrium Iron Garnet), which was placed in a microwave cavity, nonlinearly couples with microwave photon with configuring magnon-photon nonlinearly coupled oscillator mode. Those coupled modes were studied by means of additional weak microwave signal. Theoretical calculations, which consider coupled systems of resonator mode and magnetic sample, are found to be in good agreement with the experimental data.
Microwave radiation was detected from a sphere single crystal of YIG with applying both static and microwave magnetic field parallel to the [111] axis, easy magnetization axis. A disk sample was also used with applying magnetic fields parallel to the sample surface, which is perpendicular to the [111] axis. The frequencies of pumping microwave were 9.5 and 15.4 GHz. Radiated microwave was detected by a small pick-up coil wounded around a sample and analyzed by a microwave spectrum analyzer. The intensity of radiated microwave was measured as a function of time after the end of pulse pumping. As a result, relaxation time of magnon is directly determined as 19 p s which is in agreement with spin-wave relaxation time measured by other experiments.

Report

(3 results)
  • 1998 Annual Research Report   Final Research Report Summary
  • 1997 Annual Research Report
  • Research Products

    (12 results)

All Other

All Publications (12 results)

  • [Publications] V.L.Safonov: "Parametric Pair of Waves as a Nonlinear Oscillator" J.Phys.Soc.Jpn.66-7. 1916-1919 (1997)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] M.Mino: "The Onset of Auto-Oscillations of Parametrically Excited Spin-Wave Pairs" J.Phys.Soc.Jpn.67-2. 409-412 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Q.Shi: "Unitary Transformations in Weakly Nonideal Bose Gases" Phys.Letters A. 238-4. 258-264 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Q.Shi: "Observation of Nonlinear Coupled Photon-Magnon Oscillations in YIG" J.Phys.Soc.Jpn.67-9. 3283-3287 (1998)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] V.L.Safonov: "Parametric Pair of Waves as a Nonlinear Oscillator" J.Phys.Soc.Jpn.66-7. 1916-1919 (1997)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] M.Mino: "The Onset of Auto-Oscillations of Parametrically Excited Spin-Wave Pairs" J.Phys.Soc.Jpn.67-2. 409-412 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Q.Shi: "Unitary Transformations in Weakly Nonideal Bose Gases" Phys.Letters A. 238-4. 258-264 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] Q.Shi: "Observation of Nonlinear Coupled Photon-Magnon Oscillations in YIG" J.Phys.Soc.Jpn.67-9. 3283-3287 (1998)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1998 Final Research Report Summary
  • [Publications] M.Mino: "The Onset of Auto-Oscillations of Parametrically Excited Spin-Wave Pairs" J.Phys.Soc.Jpn.67-2. 409-412 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Q.Shi: "Unitary Transformations in Weakly Nonideal Bose Gases" Phys.Letters A. 238-4. 258-264 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Q.Shi: "Observation of Nonlinear Coupled Photon-Magnon Oscillations in YIG" J.Phys.Soc.Jpn.67-9. 3283-3287 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] V.L.Safonov: "Parametric Pair of Waves as a Nonlinear Oscillator" J.Phys.Soc.Jpn.66・7. 1916-1919 (1997)

    • Related Report
      1997 Annual Research Report

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Published: 1997-04-01   Modified: 2020-05-15  

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