| 研究実績の概要 |
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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