@article{mamica_spin-wave_2024,
title = {Spin-wave mode coupling in the presence of the demagnetizing field in cobalt-permalloy magnonic crystals},
author = {Sławomir Mamica},
url = {https://www.nature.com/articles/s41598-024-74923-2},
doi = {10.1038/s41598-024-74923-2},
issn = {2045-2322},
year = {2024},
date = {2024-10-03},
urldate = {2024-10-11},
journal = {Scientific Reports},
volume = {14},
number = {1},
pages = {22966},
abstract = {We present the results of studies on the non-uniform frequency shift of spin wave spectrum in a two-dimensional magnonic crystal of cobalt/permalloy under the influence of external magnetic field changes. We investigate the phenomenon of coupling of modes and, as a consequence, their hybridization. By taking advantage of the fact that compressing the crystal structure along the direction of the external magnetic field leads to an enhancement of the demagnetizing field, we analyse its effect on the frequency shift of individual modes depending on their concentration in Co. We show that the consequence of this enhancement is a shift in the coupling of modes towards higher magnetic fields. This provides a potential opportunity to design which pairs of modes and in what range of fields hybridization will occur.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{MAMICA2023171395,
title = {The influence of the demagnetizing field on the concentration of spin wave energy in two-dimensional magnonic crystals},
author = {Sławomir Mamica},
url = {https://www.sciencedirect.com/science/article/pii/S0304885323010454},
doi = {https://doi.org/10.1016/j.jmmm.2023.171395},
issn = {0304-8853},
year = {2023},
date = {2023-10-21},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {588},
pages = {171395},
abstract = {We use the Plane Wave Method to theoretically study thin-film magnonic crystals (MCs) composed of two very common magnetic materials: cobalt and permalloy. In both cases, we consider Co inclusions in the Py matrix and Py inclusions in the Co matrix. An external magnetic field is applied in the plane of the structure, leading to the formation of a demagnetizing field at the interface between the inclusions and matrix. Previous studies have shown that this field strongly affects the spectrum of spin waves, including the position and width of bandgaps. In this study, we exploit the in-plane squeezing of the MC structure to enhance the demagnetizing field. This results in the transfer of low-frequency spin waves from Py to Co, affecting the energy distribution (i.e., the spin-wave profile). The change in the concentration of spin-wave profiles leads to certain peculiarities in the spin-wave frequency spectrum. These include modes repulsion caused by hybridization, which in turn leads to the reordering of modes in the spectrum.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{BARANOWSKI2022169261,
title = {Resonance modes of periodically structuralized microwave magnetic elements},
author = {M Baranowski and Sławomir Mamica},
url = {https://www.sciencedirect.com/science/article/pii/S0304885322002128},
doi = {https://doi.org/10.1016/j.jmmm.2022.169261},
issn = {0304-8853},
year = {2022},
date = {2022-03-16},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {553},
pages = {169261},
abstract = {Here we consider a flower-like structure of a resonator consisting of six elliptical elements, referred to as petals, made from a magnetic material. The petals are positioned with their centres at the corners of a regular hexagon. Using numerical simulations (CST Studio) we examine the effect of different radial orientations of petals. We study resonance modes with a specific distribution of the electromagnetic field within the resonator as well as the effect of the rotation of petals on the field distribution. The mode character is crucial to understand the behaviour of the frequency spectrum. E.g., the rotation of petals influences significantly the frequency of the lowest mode only, while the other frequencies are almost unchanged and this effect is directly related to the profiles of modes. The system studied is a promising candidate for a tuneable component of an integrated detection system.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{MAMICA2022168690,
title = {Influence of the demagnetizing field on the spin-wave softening in bicomponent magnonic crystals},
author = {Sławomir Mamica},
url = {https://www.sciencedirect.com/science/article/pii/S0304885321009264},
doi = {https://doi.org/10.1016/j.jmmm.2021.168690},
issn = {0304-8853},
year = {2021},
date = {2021-11-11},
journal = {Journal of Magnetism and Magnetic Materials},
volume = {546},
pages = {168690},
abstract = {In bi-component magnonic crystals (MCs) demagnetizing field occurs around interfaces between a matrix and inclusions. As it is already shown this field strongly influences the spin-wave spectrum including the position and the width of band gaps and their response to the change of the external magnetic field. Here, we show its effect on the reversal of the mode order in the spectrum. The reversal of modes means that the modes which are excited mostly in the material with higher saturation magnetization have the lowest frequency than modes excited in the material with low saturation magnetization. We address this effect to the mode-dependent softening of spin waves resulting from the growing influence of the demagnetizing field while the external magnetic field lowers. The effect gives a possibility of the concentration of spin waves (i.e. the spatial distribution of their energy) in one of the constituent materials (the spin wave is excited much stronger in one material than in the other), the matrix or scattering centres, by the external magnetic field. As an example, we study planar bi-component MCs consisting of cobalt inclusions in permalloy matrix, as well as Py inclusions in Co matrix. We show that in both cases lowering external magnetic field drives down in the spectrum these modes which are excited mostly in Co. Moreover, the concentration of such modes in Co is enhanced.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}

@article{doi:10.1063/5.0045142,
title = {Phase resolved observation of spin wave modes in antidot lattices},
author = {Felix Groß and Mateusz Zelent and Ajay Gangwar and Sławomir Mamica and Paweł Gruszecki and Matthias Werner and Gisela Schütz and Markus Weigand and Eberhard J Goering and Christian H Back and Maciej Krawczyk and Joachim Gräfe},
url = {https://doi.org/10.1063/5.0045142},
doi = {10.1063/5.0045142},
year = {2021},
date = {2021-06-10},
journal = {Appl. Phys. Lett.},
volume = {118},
number = {23},
pages = {232403},
abstract = {Antidot lattices have proven to be a powerful tool for spin wave band structure manipulation. Utilizing time-resolved scanning transmission
x-ray microscopy, we are able to experimentally image edge-localized spin wave modes in an antidot lattice with a lateral confinement down
to <80nm x 130 nm. At higher frequencies, spin wave dragonfly patterns formed by the demagnetizing structures of the antidot lattice are
excited. Evaluating their relative phase with respect to the propagating mode within the antidot channel reveals that the dragonfly modes are
not directly excited by the antenna but need the propagating mode as an energy mediator. Furthermore, micromagnetic simulations reveal
that additional dispersion branches exist for a tilted external field geometry. These branches correspond to asymmetric spin wave modes that
cannot be excited in a non-tilted field geometry due to the symmetry restriction. In addition to the band having a negative slope, these asymmetric
modes also cause an unexpected transformation of the band structure, slightly reaching into the otherwise empty bandgap between
the low frequency edge modes and the fundamental mode. The presented phase resolved investigation of spin waves is a crucial step for spin
wave manipulation in magnonic crystals.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}