Professor Mitsuru Takenaka, in collaboration with a research group led by Professor Satoshi Nakatsuji of the Graduate School of Science, has demonstrated that the antiferromagnetic material Mn3Sn can undergo ultrafast switching of its magnetic state using an extremely short pulse of 40 picoseconds. They demonstrated that the antiferromagnetic device used in this study enables picosecond switching that achieves both significantly reduced heat generation and high durability through spin-orbit torque based on angular momentum transfer independent of heat. Furthermore, we demonstrated that similar switching is possible using 60-picosecond photocurrent pulses generated by combining a laser operating in the communication wavelength band with a photodetector. This also constitutes a successful fundamental demonstration of “spintronics photoconversion,” which converts optical signals into electrical signals and connects them directly to non-volatile memory for writing. The joint research group included Professor Ryotaro Arita (also Team Director at the RIKEN Center for Emergent Matter Science) from the Graduate School of Science; Assistant Professor Kotaro Shimizu and Professor Tetsuya Iizuka from the Graduate School of Engineering; Associate Professor Shinji Miwa from the Institute for Solid State Physics; and Senior Researcher Kota Kondo (currently Associate Professor at the Osaka University Interdisciplinary Research Institute) from the RIKEN Center for Emergent Matter Science. The research paper was published online in the international scientific journal “Science” on May 14.
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