The nonlinear response of a magnetic thin film subject to microwave radiation is quantitatively predicted in the steady state. Three- and four-magnon processes are shown to cause this nonlinearity with a strong dependence on magnetic bias field, microwave frequency, and applied power. Predictions are calculated using large-scale micromagnetic simulations executed on graphics processing units (GPUs) and include thermal fluctuations. A 2-D simulation paradigm is proposed for reducing the resource requirements while being able to capture the qualitative and quantitative behavior of the significant microwave-ferromagnet interactions in the parallel pumping configuration. A mathematical formalism specific to thin films is then developed to explain the aforementioned behavior of such magnetic materials based on their predicted magnon dispersion relation. The simulated predictions for high-power (nonlinear) performance are in close agreement with experiment even though the material parameters are only taken from low-power (linear) data.
|Original language||English (US)|
|Number of pages||9|
|Journal||IEEE Transactions on Microwave Theory and Techniques|
|State||Published - Feb 2020|
Bibliographical noteFunding Information:
Manuscript received May 22, 2019; revised August 31, 2019; accepted October 17, 2019. Date of publication December 17, 2019; date of current version January 31, 2020. This work was supported in part by the U.S. Defense Advanced Research Projects Agency (DARPA) under Grant W911NF-17-1-0100, in part by the Center for Micromagnetics and Information Technologies, in part by NSF through Extreme Science and Engineering Discovery Environment (XSEDE) under Grant ACI-1548562, and in part by the Minnesota Supercomputing Institute (MSI). (Corresponding author: Aneesh Venugopal.) A. Venugopal and R. H. Victora are with the Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, MN 55455 USA (e-mail: email@example.com; firstname.lastname@example.org).
- Ferromagnetic resonance (FMR)
- frequency-selective limiters (FSLs)
- nonlinear response
- parallel pump
- parametric pumping
- spin waves
- yttrium iron garnet (YIG)