| 2. | Victor A L'vov, Yulia Kharlan, Vladimir O Golub Nonrelaxational FMR peak broadening in spatially inhomogeneous films Journal of Magnetism and Magnetic Materials, 580 , pp. 170906, 2023, ISSN: 0304-8853. Abstract | Links | BibTeX @article{LVOV2023170906,
title = {Nonrelaxational FMR peak broadening in spatially inhomogeneous films},
author = {Victor A L'vov and Yulia Kharlan and Vladimir O Golub},
url = {https://www.sciencedirect.com/science/article/pii/S0304885323005565},
doi = {https://doi.org/10.1016/j.jmmm.2023.170906},
issn = {0304-8853},
year = {2023},
date = {2023-08-15},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {580},
pages = {170906},
abstract = {The modification of magnetic properties in spatially inhomogeneous epitaxial films of magnetic shape memory alloys in martensitic state with the temperature variation has been studied. The proposed theoretical model is based on Landau theory of martensitic transformation and statistical model of martensitic state. It was shown that that spatial inhomogeneity of the material leads to the dispersion of local martensitic transformation temperatures resulting in the variation of local magnetic anisotropy values. This model allows describing the dramatic ferromagnetic resonance line broadening observed in the experiments in epitaxial films of magnetic shape memory alloys at low temperatures.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The modification of magnetic properties in spatially inhomogeneous epitaxial films of magnetic shape memory alloys in martensitic state with the temperature variation has been studied. The proposed theoretical model is based on Landau theory of martensitic transformation and statistical model of martensitic state. It was shown that that spatial inhomogeneity of the material leads to the dispersion of local martensitic transformation temperatures resulting in the variation of local magnetic anisotropy values. This model allows describing the dramatic ferromagnetic resonance line broadening observed in the experiments in epitaxial films of magnetic shape memory alloys at low temperatures. |
| 1. | Arezoo Etesamirad, Yulia Kharlan, Rodolfo Rodriguez, Igor Barsukov, Roman Verba Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking Phys. Rev. Appl., 19 , pp. 044087, 2023. Abstract | Links | BibTeX @article{PhysRevApplied.19.044087,
title = {Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking},
author = {Arezoo Etesamirad and Yulia Kharlan and Rodolfo Rodriguez and Igor Barsukov and Roman Verba},
url = {https://link.aps.org/doi/10.1103/PhysRevApplied.19.044087},
doi = {10.1103/PhysRevApplied.19.044087},
year = {2023},
date = {2023-04-27},
journal = {Phys. Rev. Appl.},
volume = {19},
pages = {044087},
publisher = {American Physical Society},
abstract = {Nanomagnets are the building blocks of many existing and emergent spintronic technologies. The magnetization dynamics of nanomagnets is often dominated by nonlinear processes, which have been recently shown to have many surprising features and far-reaching implications for applications. Here we develop a theoretical framework uncovering the selection rules for multimagnon processes and discuss their underlying mechanisms. For its technological relevance, we focus on the degenerate three-magnon process in thin elliptical nanodisks to illustrate our findings. We parameterize the selection rules through a set of magnon interaction coefficients which we calculate using micromagnetic simulations. We postulate the selection rules and investigate how they are altered by perturbations that break the symmetry of static magnetization configuration and spatial spin-wave profiles and that can be realized by applying off-symmetry-axis or nonuniform magnetic fields. Our work provides the phenomenological understanding of the mechanics of magnon interaction as well as the formalism for determining the interaction coefficients from simulations and experimental data. Our results serve as a guide to analyze the magnon processes inherently present in spin-torque devices in order to boost their performance or to engineer a specific nonlinear response in a nanomagnet used in a neuromorphic or quantum magnonic application.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Nanomagnets are the building blocks of many existing and emergent spintronic technologies. The magnetization dynamics of nanomagnets is often dominated by nonlinear processes, which have been recently shown to have many surprising features and far-reaching implications for applications. Here we develop a theoretical framework uncovering the selection rules for multimagnon processes and discuss their underlying mechanisms. For its technological relevance, we focus on the degenerate three-magnon process in thin elliptical nanodisks to illustrate our findings. We parameterize the selection rules through a set of magnon interaction coefficients which we calculate using micromagnetic simulations. We postulate the selection rules and investigate how they are altered by perturbations that break the symmetry of static magnetization configuration and spatial spin-wave profiles and that can be realized by applying off-symmetry-axis or nonuniform magnetic fields. Our work provides the phenomenological understanding of the mechanics of magnon interaction as well as the formalism for determining the interaction coefficients from simulations and experimental data. Our results serve as a guide to analyze the magnon processes inherently present in spin-torque devices in order to boost their performance or to engineer a specific nonlinear response in a nanomagnet used in a neuromorphic or quantum magnonic application. |
