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2018 Fiscal Year Annual Research Report

Quantitative calculation of magnon transport properties of insulators

Research Project

Project/Area Number 17K14102
Research InstitutionTohoku University

Principal Investigator

Barker Joseph  東北大学, 金属材料研究所, 特任助教 (10746910)

Project Period (FY) 2017-04-01 – 2019-03-31
Keywordsspintronics / magnons / transport / yttrium / iron garnet / antiferromagnet
Outline of Annual Research Achievements

I have implemented a quantum thermostat for atomistic spin dynamics. I have rigorously checked its correctness in simple systems by comparison with analytically derivable results and in complex systems by comparing to experiments. The manuscript for this result is in the final stages of preparation for submission.

I have succeeded in calculating magnon transport properties in the complex magnetic insulator Yttrium Iron Garnet (YIG). This includes the magnon spin conductivity and the magnon heat conductivity. This work required the quantum thermostat to achieve correct results at all temperatures. The magnon spin conductivity shows excellent agreement with experimental measurements but the heat conductivity shows a difference at higher temperature which may be due to defects or phonons. The manuscript of this work will soon be written and submitted for publication.

I have also investigated magnon transport in antiferromagnetic insulators, notably Cr2O3, in collaboration with the experimental group of Prof. Eiji Saitoh (Tohoku) and theorists at the Johannes Gutenberg University, Mainz. In YIG/Cr2O3/Pt devices the Cr2O3 can be used to switch spin currents on and off. This work was published in Nature Materials. The unusual temperature dependence of anisotropy in Cr2O3 is important for this and I am currently preparing a manuscript where my calculations show the dipole anisotropy in this material has an anomalous behaviour.

  • Research Products

    (5 results)

All 2018 Other

All Int'l Joint Research (1 results) Journal Article (1 results) (of which Int'l Joint Research: 1 results,  Peer Reviewed: 1 results) Presentation (3 results) (of which Int'l Joint Research: 2 results,  Invited: 2 results)

  • [Int'l Joint Research] JGU University Mainz(Germany)

    • Country Name
      Germany
    • Counterpart Institution
      JGU University Mainz
  • [Journal Article] Spin colossal magnetoresistance in an antiferromagnetic insulator2018

    • Author(s)
      Qiu Zhiyong、Hou Dazhi、Barker Joseph、Yamamoto Kei、Gomonay Olena、Saitoh Eiji
    • Journal Title

      Nature Materials

      Volume: 17 Pages: 577~580

    • DOI

      10.1038/s41563-018-0087-4

    • Peer Reviewed / Int'l Joint Research
  • [Presentation] Atomistic simulations of spin caloritronic properties of complex magnets2018

    • Author(s)
      Barker Joseph
    • Organizer
      Spin Mechanics V, Les Houches, France
    • Int'l Joint Research / Invited
  • [Presentation] Calculating spin transport properties in magnetic insulators2018

    • Author(s)
      Barker Joseph
    • Organizer
      PASPS10, Linz, Austria
    • Int'l Joint Research / Invited
  • [Presentation] Atomistic spin dynamics calculations with a quantum thermostat2018

    • Author(s)
      Barker Joseph
    • Organizer
      Collective Spin Excitations in Nanostructures KITS Workshop, Beijing, China

URL: 

Published: 2019-12-27  

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