Related Experiment Video
Updated: May 14, 2025

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains
Published on: July 20, 2022
Dynamically Tunable Magnon-Magnon Coupling in a Perpendicular Anisotropy Magnetic Garnet-Ferromagnet Bilayer
Yabin Fan1, Takian Fakhrul1,2, Justin T Hou3,4
1Massachusetts Institute of Technology, Department of Materials Science and Engineering, Cambridge, Massachusetts 02139, USA.
Abstract:
We experimentally explore the interfacial coherent spin pumping in the magnon-magnon hybridized regime of a perpendicular anisotropy ferrimagnetic insulator (Bi-substituted yttrium iron garnet, or BiYIG) and ferromagnetic metal (permalloy, or Py) bilayer. In addition to the interfacial exchange coupling-induced avoided crossings between the uniform modes of BiYIG and Py, we observe that the gap opening can be tailored by changing the relative orientations of the BiYIG and Py magnetizations due to a purely dynamic interaction. The avoided-crossing gap opening is small (large) when BiYIG and Py magnetizations are nearly perpendicular (partially collinear) to each other, indicating that interfacial fieldlike torque from spin pumping plays a dominant role. Macrospin simulations with a sizable fieldlike spin-pumping torque agree with the gap opening trend observed in the experiments.
Related Concept Videos
Ferromagnetism
Magnetic Susceptibility and Permeability
When diamagnetic materials are placed under an external magnetic field, the moments opposite to the field are induced. Hence, the susceptibility for diamagnets has a minimal negative value of 10-5–10-6. Since...
Paramagnetism
Diamagnetism
Diamagnetism was discovered by Anton Brugmans in 1778 when he observed that bismuth gets repelled by magnetic fields, thus theorizing that diamagnets get repelled by magnets....
Magnetic Damping
If, however, the bob is a slotted metal plate, the magnet produces a much smaller effect. When a slotted metal plate enters the field, an emf is induced by the change in flux; however, it is less effective because the slots limit the...
Magnetostatic Boundary Conditions

