2025-03-2-13 東京大学,慶應義塾大学,科学技術振興機構
本研究成果の模式図
＜関連情報＞
- https://www.issp.u-tokyo.ac.jp/maincontents/news2.html?pid=26575
- https://www.issp.u-tokyo.ac.jp/news/wp-content/uploads/2025/03/0313_press_magnon.pdf
- https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.134.106702
パルス光によって励起されるスピンダイナミクスのゆらぎ Fluctuations in Spin Dynamics Excited by Pulsed Light
Tetsuya Sato, Shinichi Watanabe, Mamoru Matsuo, and Takeo Kato
Physical Review Letters Published: 12 March, 2025
DOI:https://doi.org/10.1103/PhysRevLett.134.106702
Abstract
We theoretically investigate nonequilibrium spin fluctuations in a ferromagnet induced by a light pulse. Using a Lindblad equation consistent with the Landau-Lifshitz-Gilbert equation, we compute the autocorrelation function of magnetization. Our analysis reveals that this function comprises both thermal and nonequilibrium components. To examine the latter in detail, we introduce a Fano factor similar to nonequilibrium current noise in electronic circuits. We demonstrate that this factor encapsulates insights into the transfer of spin units to the environment. Our findings lay the groundwork for nonequilibrium spin noise spectroscopy, offering valuable insights into spin relaxation dynamics.
