Gyromagnetic bifurcation in a levitated ferromagnetic particle

浮上した強磁性粒子における磁気回転分岐

佐藤 哲也*; 加藤 岳生*; 大上 能悟*; 松尾 衛

Sato, Tetsuya*; Kato, Takeo*; Oue, Daigo*; Matsuo, Mamoru

We examine the mechanical rotation of a levitated magnetic particle that is induced by ferromagnetic resonance under microwave irradiation. We show that two stable solutions appear in a certain range of parameters by bifurcation when the rotation frequency is comparable to the microwave frequency. This phenomenon originates from the coexistence of the Barnett and the Einstein-de Haas effects. We also reveal that this measurement is sensitive to the strength of the spin-rotation coupling. Our work provides a platform for accessing a microscopic relaxation process from spin to macroscopic rotation.