DATE2022.03.07 #Press Releases

Ultrafast Ferromagnetism in Oxide Thin Films

Disclaimer: machine translated by DeepL which may contain errors.

- Suggests the possibility of new spin manipulation by light!-

University of Hyogo

The University of Tokyo, Graduate School of Science

Summary

Professor Daiki Wadachi and Yujun Zhang of the Graduate School of Science, University of Hyogo, in collaboration with Associate Professor Tsukasa Katayama (at the time of the research, now Associate Professor at Hokkaido University) and Assistant Professor Akira Chikamatsu (at the time of the research, now Associate Professor at Ochanomizu University) of the Graduate School of Science, The University of Tokyo, and a research group of Helmholtz-Zentrum Berlin (now Associate Professor at Ochanomizu University) and their research group at Helmholtz-Zentrum Berlin, Germany, have successfully observed ultrafast changes in the magnetic structure in a thin film of the cobalt oxide _GdBaCo2O5.5 by time-resolved measurements of magnetic circular dichroism and resonant magnetic diffraction of soft X-ray reflectivity. As a result, they revealed spin dynamics in which the antiferromagnetic thin film becomes ferromagnetic and magnetization increases after an ultrafast time of picoseconds (= one trillionth of a second) after laser irradiation.

Ultrafast spin dynamics is attracting a great deal of attention from the viewpoints of basic science and applications, because it will lead to future ultrafast memory and other applications based on laser irradiation. This discovery demonstrates that lasers provide a new means of manipulating thin films to instantaneously change their magnetic structure. It is expected that research on spin manipulation and various materials using light will become more active in the future, and the development of next-generation optical devices based on such manipulation will be promoted.

The results were published in the British scientific journal Communications Physics on March 7 at 10:00 a.m. (local time).

Figure: Image of the photo-excited state of cobalt spin. Laser irradiation increases the magnetization along the horizontal axis.

For more information, please visit the website of the University of Hyogo.