2018 Fiscal Year Annual Research Report
Quantitative calculation of magnon transport properties of insulators
| Project/Area Number |
17K14102
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| Research Institution | Tohoku University |
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Principal Investigator |
Barker Joseph 東北大学, 金属材料研究所, 特任助教 (10746910)
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| Project Period (FY) |
2017-04-01 – 2019-03-31
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| Keywords | spintronics / magnons / transport / yttrium / iron garnet / antiferromagnet |
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| 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.
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Research Products
(5 results)
