Electrical Excitation and Detection of Chiral Magnons in a Compensated Ferrimagnetic Insulator
Ledong Wang, Laichuan Shen, Hao Bai, Hengan Zhou, Ka Shen, Wanjun Jiang
Abstract
Magnon chirality refers to the precessional handedness of magnetization around the external magnetic field, which is fixed as right-handed in ferromagnets. Compensated ferrimagnets accommodate parallel and antiparallel configurations of net magnetization and angular momentum, and thus serve as an ideal platform for studying magnon chirality. Through performing spin-torque ferromagnetic resonance experiments, we experimentally study the reversal of low-frequency magnon chirality across the magnetization and angular momentum compensation temperatures in a Gd_{3}Fe_{5}O_{12}/Pt bilayer. In particular, we demonstrate that dampinglike spin torque could sensitively excite and detect the reversal of low-frequency magnon chirality. By solving the coupled Landau-Lifshitz-Gilbert equations, the close correlation between the reversal of low-frequency magnon chirality and the sign of net angular momenta is established. The electrical excitation and detection of low-frequency magnon chirality in compensated ferrimagnetic insulators could be useful for building chiral spintronics.