Abstract
We analyze the magnetic mode structure of axially magnetized finite-length nanoscopic cylinders in a regime where the exchange interaction dominates, along with simulations of the mode frequencies of the ferrimagnet yttrium iron garnet. For the bulk modes, we find that the frequencies can be represented by an expression given by Herring and Kittel by using wavevector components obtained by fitting the mode patterns emerging from these simulations. In addition to the axial, radial, and azimuthal modes that are present in an infinite cylinder, we find localized "cap modes"that are "trapped"at the top and bottom cylinder faces by the inhomogeneous dipole field emerging from the ends. Semiquantitative explanations are given for some of the modes, in terms of a one-dimensional Schrodinger equation, which is valid in the exchange-dominant case. The assignment of the azimuthal-mode number is carefully discussed, and the frequency splitting of a few pairs of nearly degenerate modes is determined through the beat pattern emerging from them.
| Original language | English (US) |
|---|---|
| Article number | 064007 |
| Journal | Physical Review Applied |
| Volume | 16 |
| Issue number | 6 |
| DOIs | |
| State | Published - Dec 2021 |
Funding
This research is carried out under the support of the U.S. Department of Energy through Grant No. DE-SC0014424. This research is supported, in part, through the computational resources and staff contributions provided by the Quest High-Performance Computing Facility at Northwestern University, which is jointly supported by the Office of the Provost, the Office for Research, and Northwestern University Information Technology.
ASJC Scopus subject areas
- General Physics and Astronomy