Publications

@article{doi:10.1021/acsami.4c02366,,

title = {Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures},

author = {Mateusz Gołębiewski and R Hertel and M d’Aquino and V I Vasyuchka and M Weiler and P Pirro and Maciej Krawczyk and S Fukami and H Ohno and J Llandro},

url = {https://doi.org/10.1021/acsami.4c02366},

doi = {10.1021/acsami.4c02366},

year  = {2024},

date = {2024-04-22},

urldate = {2024-04-22},

journal = {ACS Applied Materials & Interfaces},

volume = {0},

issue = {0},

pages = {0},

abstract = {Expanding upon the burgeoning discipline of magnonics, this research elucidates the intricate dynamics of spin waves (SWs) within three-dimensional nanoenvironments. It marks a shift from traditionally used planar systems to exploration of magnetization configurations and the resulting dynamics within 3D nanostructures. This study deploys micromagnetic simulations alongside ferromagnetic resonance measurements to scrutinize magnetic gyroids, periodic chiral configurations composed of chiral triple junctions with a period in nanoscale. Our findings uncover distinctive attributes intrinsic to the gyroid network, most notably the localization of collective SW excitations and the sensitivity of the gyroid’s ferromagnetic response to the orientation of the static magnetic field, a correlation closely tied to the crystallographic alignment of the structure. Furthermore, we show that for the ferromagnetic resonance, multidomain gyroid films can be treated as a magnonic material with effective magnetization scaled by its filling factor. The implications of our research carry the potential for practical uses such as an effective, metamaterial-like substitute for ferromagnetic parts and lay the groundwork for radio frequency filters. The growing areas of 3D magnonics and spintronics present exciting opportunities to investigate and utilize gyroid nanostructures for signal processing purposes.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{https://doi.org/10.1002/qute.202400015,

title = {Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode-Revision},

author = {N Kumar and Paweł Gruszecki and Mateusz Gołębiewski and Jarosław W Kłos and Maciej Krawczyk},

url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202400015},

doi = {https://doi.org/10.1002/qute.202400015},

year  = {2024},

date = {2024-03-29},

urldate = {2024-03-29},

journal = {Advanced Quantum Technologies},

pages = {2400015},

abstract = {Abstract Spin waves (SWs) are promising objects for signal processing and future quantum technologies due to their high microwave frequencies with corresponding nanoscale wavelengths. However, the nano-wavelength SWs generated so far are limited to low frequencies. In the paper, using micromagnetic simulations, it is shown that a microwave-pumped SW mode confined to the cavity of a thin film magnonic crystal (MC) can be used to generate waves at tens of GHz and wavelengths well below 50 nm. These multi-frequency harmonics of the fundamental cavity mode are generated when the amplitude of the pumping microwave field exceeds a threshold, and their intensities then scale linearly with the field intensity. The frequency of the cavity mode is equal to the ferromagnetic resonance frequency of the planar ferromagnetic film, which overlaps with the magnonic bandgap, providing an efficient mechanism for confinement and magnetic field tunability. The effect reaches saturation when the microstrip feed line covers the entire cavity, making the system feasible for realization.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevB.109.054430,,

title = {Impact of surface anisotropy on the spin-wave dynamics in a thin ferromagnetic film},

author = {Krzysztof Szulc and Julia Kharlan and P Bondarenko and Elena Tartakovskaya and Maciej Krawczyk

},

doi = {10.1103/PhysRevB.109.054430},

year  = {2024},

date = {2024-02-26},

journal = {Phys. Rev. B},

volume = {109},

issue = {5},

pages = {054430},

abstract = {The spin-wave dynamics in the thin CoFeB film in Damon-Eshbach geometry are studied in three cases of boundary conditions—free boundary conditions, symmetrical surface anisotropy, and one-sided surface anisotropy. The analytical model created by Wolfram and De Wames was extended to include perpendicular surface anisotropy in boundary conditions. Its comparison with numerical simulations demonstrates perfect agreement between the approaches. The analysis of the dispersion relation indicates that the presence of surface anisotropy increases the avoided crossing size between the Damon-Eshbach mode and perpendicular standing modes. Additionally, asymmetrical one-sided surface anisotropy induces nonreciprocity in the dispersion relation. In-depth analysis of the avoided crossing size is conducted for systems with different boundary conditions, different thicknesses, surface anisotropy constant values, and external magnetic fields. It shows the significant role of the strength of surface localization of the Damon-Eshbach mode and the symmetry of perpendicular standing modes in the avoided crossing broadening. Interestingly, for a specific set of parameters, the interaction between the particular modes can be suppressed, resulting in a mode crossing. Such a crossing, which occurs only for one direction of the wave vector in a one-sided surface anisotropy system, can be utilized in nonreciprocal devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Serebryannikov:24,

title = {Thermally mediated transmission-mode deflection of terahertz waves by lamellar metagratings containing a phase-change material},

author = {Andriy E Serebryannikov and A Lakhtakia and E Ozbay},

url = {https://opg.optica.org/ome/abstract.cfm?URI=ome-14-3-745},

doi = {10.1364/OME.511804},

year  = {2024},

date = {2024-02-15},

journal = {Opt. Mater. Express},

volume = {14},

number = {3},

pages = {745--758},

abstract = {The planewave-response characteristics of simple lamellar metagratings exhibiting thermally mediated transmission-mode deflection (blazing) were numerically investigated, the unit cell of each metagrating containing a phase-change material chosen to be indium antimonide (InSb). Thermal control arises from the use of InSb in its insulator phase and the vicinity of the vacuum state. Metagratings of type A comprise parallel rods of InSb on silicon-dioxide substrate, whereas the substrate is also made of InSb in metagratings of type B. Both types exhibit thermally controllable deflection and asymmetric transmission, which occur when the real part of the relative permittivity of InSb is high. Narrowband features in the sub-diffraction regime may appear in a wide frequency range which involves the vicinity of the vacuum state, the real part of the relative permittivity of InSb being low then.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Serebryannikov2024,

title = {Exploring localized ENZ resonances and their role in superscattering, wideband invisibility, and tunable scattering},

author = {Andriy E. Serebryannikov and E Ozbay},

doi = {10.1038/s41598-024-51503-y},

year  = {2024},

date = {2024-01-18},

urldate = {2024-01-18},

journal = {Scientific Reports},

volume = {14},

number = {1},

pages = {1580},

abstract = {While the role and manifestations of the localized surface plasmon resonances (LSPRs) in anomalous scattering, like superscattering and invisibility, are quite well explored, the existence, appearance, and possible contribution of localized epsilon-near-zero (ENZ) resonances still invoke careful exploration. In this paper, that is done along with a comparison of the resonances of two types in the case of thin-wall cylinders made of lossy and loss-compensated dispersive materials. It is shown that the localized ENZ resonances exist and appear very close to the zero-permittivity regime, i.e., at near-zero but yet negative permittivity that is similar to the ENZ modes in thin planar films. Near- and far-field characteristics of the superscattering modes are investigated. The results indicate that the scattering regimes arising due to LSPRs and localized ENZ resonances are distinguishable in terms of the basic field features inside and around the scatterer and differ in their contribution to the resulting scattering mechanism, e.g., in terms of the occupied frequency and permittivity ranges as well as the sensitivity to the wall thickness variations. When the losses are either weak or tend to zero due to the doping with gain enabling impurities, the sharp peaks of the scattering cross-section that are yielded by the resonances can be said to be embedded into the otherwise wide invisibility range. In the case of lossy material, a wide and continuous invisibility range is shown to appear not only due to a small total volume of the scatterer in the nonresonant regime, but also because high-Q superscattering modes are suppressed by the losses. For numerical demonstration, indium antimonide, a natural lossy material, and a hypothetical, properly doped material with the same real part of the permittivity but lower or zero losses are considered. In the latter case, variations of permittivity with a control parameter can be adjusted in such a way that transitions from one superscattering mode to another can be achieved. In turn, transition from the strong-scattering to the invisibility regime is possible even for the original lossy material. The basic properties of the studied superscattering modes may be replicable in artificial structures comprising natural low-loss materials.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ma17010260,

title = {Using Thin Films of Phase-Change Material for Active Tuning of Terahertz Waves Scattering on Dielectric Cylinders},

author = {A O Cakmak and E Colak and Andriy E Serebryannikov},

url = {https://www.mdpi.com/1996-1944/17/1/260},

doi = {10.3390/ma17010260},

isbn = {1996-1944},

year  = {2024},

date = {2024-01-04},

journal = {Materials},

volume = {17},

number = {1},

abstract = {The scattering of electromagnetic waves by isotropic dielectric cylinders can be dramatically modified by means of vanadium dioxide (VO2) thin-film coatings. Efficient dynamic control of scattering is achieved due to the variations in material parameters realizable by means of external biasing. In this paper, we study the scattering of terahertz waves in a case where the coating shells are made of VO2, a phase-change material, whose thin films may work rather as electromagnetic phase screens in the insulator material phase, but as lossy quasi-metallic components in the metallic material phase. The shells that uniformly cover the dielectric cylinders are investigated. Attention will be paid to the demonstration of the potential of VO2 in the external control of diverse scattering regimes of the dielectric-VO2 core-shell scatterer, while conductivity of VO2 corresponds to rather insignificant variations in temperature. In line with the purposes of this work, it is shown that the different resonant and nonresonant regimes have different sensitivity to the variations in VO2 conductivity. Both the total scattering cross section and field distributions inside and around the core are studied, as well as the angle-dependent scattering cross section.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{JANARDHANAN2024171570,

title = {Spin wave dynamics in CoFeB bilayers with wedged Au spacer},

author = {Sreedevi Janardhanan and Sławomir Mielcarek and H Głowiński and D Kiphart and P Kuświk and Aleksandra Trzaskowska},

doi = {https://doi.org/10.1016/j.jmmm.2023.171570},

year  = {2024},

date = {2024-01-01},

journal = {Journal of Magnetism and Magnetic Materials},

volume = {589},

pages = {171570},

abstract = {This paper presents the experimental studies of ferromagnetic layers separated by a heavy metal wedge. The studied system consists of two thin layers of CoFeB separated by a wedged Au spacer. By performing Brillouin light scattering measurements of the spin-wave dispersion relations, and dependences on the magnetic field, we extract magnetic parameters in the studied ferromagnetic layers as a function of heavy metal thickness. We concluded that for thin ferromagnetic double layers, the magnetic properties strongly depend on the thickness of the wedge gold layer spacer. In particular, the presence of perpendicular magnetic anisotropy diminishes as the thickness of the magnetic material is increased, and at the spacers thicker than 2.5 nm the dynamic coupling between propagating spin waves in both layers is negligible. These findings have potential advantages for the development of future spintronic devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10.1063/5.0162561,

title = {Giant four-fold magnetic anisotropy in nanotwinned NiMnGa epitaxial films},

author = {P V Bondarenko and Julia Kharlan and S A Bunyaev and O Salyuk and I R Aseguinolaza and J M Barandiaran and G N Kakazei and V Chernenko and V O Golub},

doi = {10.1063/5.0162561},

year  = {2023},

date = {2023-12-22},

urldate = {2023-12-22},

journal = {APL Materials},

volume = {11},

number = {12},

pages = {121114},

abstract = {A giant four-fold magnetic anisotropy (with an anisotropy field up to 4 kOe) was observed in the twinned NiMnGa epitaxial film. Its appearance is explained in terms of moderate coupling between twin variants having strong uniaxial magnetocrystalline anisotropies directed orthogonally when the intertwin exchange field is comparable with the anisotropy field. This finding paves the way to increase the order of magnetic anisotropy in a many-component system while keeping the value of the anisotropy field by tuning the intercomponent exchange strength and can be extended to exchange-coupled multilayers and arrays of nanoelements.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{janardhanan_scirep_2023,

title = {Investigation of spin wave dynamics in Au/CoFeB/Au multilayers with perpendicular magnetic anisotropy},

author = {Sreedevi Janardhanan and Sławomir Mielcarek and H Głowiński and M Kowacz and Maciej Krawczyk and Aleksandra Trzaskowska

},

year  = {2023},

date = {2023-12-15},

journal = {Scientific Report},

volume = {13},

pages = {22494 },

abstract = {We have carried out an experimental investigation of the spin-wave dynamics in the Au/CoFeB/Au multilayer consisting of a ferromagnetic film with thicknesses of 0.8, 0.9 and 1.0 nm. We employed the Brillouin light scattering spectroscopy to measure the frequency of the spin waves in dependence on the wave vector. Additionally, we characterized the samples by ferromagnetic resonance measurements. We found that the considered samples exhibit perpendicular magnetic anisotropy with low damping, indicating small pumping effects. Furthermore, we found a nonreciprocal dispersion relation pointing at a non-negligible Dzyaloshinskii–Moriya interaction. These results make the Au/CoFeB/Au multilayer a compelling subject for further analysis and as a potential material for future applications within magnonics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{ma16227110,

title = {Modeling of Charge Injection, Recombination, and Diffusion in Complete Perovskite Solar Cells on Short Time Scales},

author = {Krzysztof Szulc and K Pydzińska-Białek and M Ziółek},

url = {https://www.mdpi.com/1996-1944/16/22/7110},

doi = {10.3390/ma16227110},

isbn = {1996-1944},

year  = {2023},

date = {2023-11-10},

journal = {Materials},

volume = {16},

number = {22},

pages = {7110},

abstract = {A model of charge population decay upon ultrafast optical pulse excitation in complete, working perovskite solar cells is proposed. The equation, including charge injections (extractions) from perovskite to contact materials, charge diffusion, and charge recombination via first-, second-, and third-order processes, is solved using numerical simulations. Results of simulations are positively verified by broadband transient absorption results of mixed halide, triple-cation perovskite (FA0.76MA0.19Cs0.05Pb(I0.81Br0.19)3). The combined analytical and experimental findings reveal the best approaches for the proper determination of the crucial parameters that govern charge transfer dynamics in perovskite solar cells on picosecond and single nanosecond time scales. Measurements from both electron and hole transporting layer sides under different applied bias potentials (zero and close to open circuit potential) and different pump fluence (especially below 5 μJ/cm2), followed by fitting of parameters using numerical modeling, are proposed as the optimal methodology for describing the processes taking place in efficient devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevB.108.184407,

title = {Bidirectional magnon-driven bimeron motion in ferromagnets},

author = {X Liang and J Lan and G Zhao and Mateusz Zelent and Maciej Krawczyk and Y Zhou},

url = {https://link.aps.org/doi/10.1103/PhysRevB.108.184407},

doi = {10.1103/PhysRevB.108.184407},

year  = {2023},

date = {2023-11-08},

journal = {Phys. Rev. B},

volume = {108},

number = {8},

issue = {18},

pages = {184407},

abstract = {As the in-plane magnetized counterparts of skyrmions in two dimensions, magnetic bimerons are swirling topological spin textures consisting of two merons. Here we theoretically and numerically investigate the dynamics of a bimeron induced by the monochromatic spin wave in a ferromagnetic thin film. The micromagnetic simulation results reveal that unlike the ferromagnetic skyrmion reported in previous studies, the bimeron can be pushed away from (or pulled towards) the wave source at the low (high) spin wave frequency. These numerical results are in line with the particle collision model formulating the interplay between the spin wave and magnetic bimeron. Our findings provide guidelines for constructing future bimeron-based spintronic devices with ultralow energy consumption.},

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},

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{DHIMAN2023171338,

title = {Hysteresis of magnetization statics and dynamics in [Pt/Co] multilayer},

author = {A.K. Dhiman and R. Gieniusz and J. Kisielewski and P. Mazalski and M. Matczak and F. Stobiecki and Paweł Gruszecki and Maciej Krawczyk and A. Lynnyk and A. Maziewski},

url = {https://www.sciencedirect.com/science/article/pii/S0304885323009885},

doi = {https://doi.org/10.1016/j.jmmm.2023.171338},

isbn = {0304-8853},

year  = {2023},

date = {2023-10-11},

journal = {Journal of Magnetism and Magnetic Materials},

volume = {587},

number = {171338},

abstract = {The magnetic multilayer of Co separated by thin spacer layer of Pt was deposited by DC-magnetron sputtering. From the longitudinal magneto-optical Kerr effect based magnetometry and microscopy as well as magnetic force microscopy, the hybrid magnetization structure was deduced: the large size, micrometer scale magnetic domains with in-plane “core magnetization” patterned by nanometer scale domains with out-of-plane components. The hysteresis as a function of in-plane applied magnetic field of both: (i) magnetization curve measured by Superconducting Quantum Interference Device and (ii) dynamic responses measured by broadband Vector Network Analyzer spectroscopy were observed. The experimental results are well described by micromagnetic simulations. These magnetic history dependent effects were explained by magnetization cores, with in plane component, switching.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PHILIPPE2023171359,

title = {Unidirectional spin wave emission by traveling pair of magnetic field profiles},

author = {Gauthier Philippe and Mathieu Moalic and Jarosław W Kłos},

doi = {https://doi.org/10.1016/j.jmmm.2023.171359},

year  = {2023},

date = {2023-10-04},

urldate = {2023-10-04},

journal = {Journal of Magnetism and Magnetic Materials},

volume = {587},

pages = {171359},

abstract = {We demonstrate that the spin wave Cherenkov effect can be used to design the unidirectional spin wave emitter with tunable frequency and switchable direction of emission. In our numerical studies, we propose to use a pair of traveling profiles of the magnetic field which generate the spin waves, for sufficiently large velocity of their motion. In the considered system, the spin waves of shorter (longer) wavelengths are induced at the front (back) of the moving profiles and interfere constructively or destructively, depending on the velocity of the profiles. Moreover, we showed that the spin waves can be confined between the pair of traveling profiles of the magnetic field. This work opens the perspectives for the experimental studies in hybrid magnonic-superconducting systems where the magnetic vortices in a superconductor can be used as moving sources of the magnetic field driving the spin waves in the ferromagnetic subsystem.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{CENTALA2023171254,

title = {Shaping magnetization dynamics in a planar square dot by adjusting its surface anisotropy},

author = {Grzegorz Centała and Jarosław W Kłos},

url = {https://www.sciencedirect.com/science/article/pii/S0304885323009046},

doi = {https://doi.org/10.1016/j.jmmm.2023.171254},

year  = {2023},

date = {2023-09-22},

journal = {Journal of Magnetism and Magnetic Materials},

volume = {587},

pages = {171254},

abstract = {A planar square dot is one of the simplest structures confined to three dimensions. Despite its geometrical simplicity, the description of the spin wave modes in this structure is not trivial due to the competition of dipolar and exchange interactions. An additional factor that makes this description challenging are the boundary conditions depend both on non-local dipolar interactions and local surface parameters such as surface anisotropy. In the presented work, we showed how the surface anisotropy applied at the lateral faces of the dot can tune the frequency of fundamental mode in the planar CoFeB dot, magnetized in an out-of-plane direction. Moreover, we analyzed the spin wave profile of the fundamental mode and the corresponding dynamic stray field. We showed that the asymmetric application of surface anisotropy produces an asymmetric profile of dynamic stray field for square dot and can be used to tailor inter-dot coupling. The calculations were performed with the use of the finite-element method.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{JANARDHANAN2023171209,

title = {High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer},

author = {Sreedevi Janardhanan and Sławomir Mielcarek and P Kuświk and Maciej Krawczyk and Aleksandra Trzaskowska},

url = {https://www.sciencedirect.com/science/article/pii/S0304885323008594},

doi = {https://doi.org/10.1016/j.jmmm.2023.171209},

year  = {2023},

date = {2023-09-04},

journal = {Journal of Magnetism and Magnetic Materials},

volume = {586},

pages = {171209},

abstract = {The topic of this paper addresses the Brillouin light scattering (BLS) study of the spin-wave and surface acoustic wave dynamics in the multilayer consisting of Ti/Au/Co/Ni deposited on Si substrate. We make the quantitative analysis of spin-wave frequency under a range of wave vectors to determine the dispersion relation and to study the effect of the magnetic field. These findings were correlated with theoretical models to determine the magnetic system parameters, such as magnetization, Lande g factor, exchange stiffness constant etc. In addition to this, we have conducted finite element method based simulations to understand the nature of surface phonons and to determine the elastic tensor parameters for the Ti/Au/Co/Ni layer from the fitting of simulation results with the experiment data points.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{zelent_stabilization2023,

title = {Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures},

author = {Mateusz Zelent and Mathieu Moalic and Michał Mruczkiewicz and X Li and Y Zhou and Maciej Krawczyk},

doi = {10.1038/s41598-023-40236-z},

year  = {2023},

date = {2023-08-21},

journal = {Scientific Reports},

volume = {13},

issue = {1},

pages = {13572},

abstract = {Magnetic skyrmions, topological quasiparticles, are small stable magnetic textures that possess intriguing properties and potential for data storage applications. Hybrid nanostructures comprised of skyrmions and soft magnetic material can offer additional advantages for developing skyrmion-based spintronic and magnonic devices. We show that a Néel-type skyrmion confined within a nanodot placed on top of a ferromagnetic in-plane magnetized stripe produces a unique and compelling platform for exploring the mutual coupling between magnetization textures. The skyrmion induces an imprint upon the stripe, which, in turn, asymmetrically squeezes the skyrmion in the dot, increasing their size and the range of skyrmion stability at small values of Dzyaloshinskii–Moriya interaction, as well as introducing skyrmion bi-stability. Finally, by exploiting the properties of the skyrmion in a hybrid system, we demonstrate unlimited skyrmion transport along a racetrack, free of the skyrmion Hall effect.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{LVOV2023170906,

title = {Nonrelaxational FMR peak broadening in spatially inhomogeneous films},

author = {V L'vov and Julia Kharlan and V Golub},

doi = {https://doi.org/10.1016/j.jmmm.2023.170906},

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}

}

@article{centala2023,

title = {Compact localized states in magnonic Lieb lattices},

author = {Grzegorz Centała and Jarosław W Kłos},

url = {https://doi.org/10.1038/s41598-023-39816-w},

year  = {2023},

date = {2023-08-04},

journal = {Scientific Reports},

volume = {13},

issue = {1},

pages = {12676},

abstract = {Lieb lattice is one of the simplest bipartite lattices, where compact localized states (CLS) are observed. This type of localization is induced by the peculiar topology of the unit cell, where the modes are localized only on selected sublattices due to the destructive interference of partial waves. We demonstrate the possibility of magnonic Lieb lattice realization, where flat bands and CLS can be observed in the planar structure of sub-micron in-plane sizes. Using forward volume configuration, the Ga-doped YIG layer with cylindrical inclusions (without Ga content) arranged in a Lieb lattice with 250 nm period was investigated numerically (finite-element method). The structure was tailored to observe, for a lowest magnonic bands, the oscillatory and evanescent spin waves in inclusions and matrix, respectively. Such a design reproduces the Lieb lattice of nodes (inclusions) coupled to each other by the matrix with the CLS in flat bands.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{sobucki2023b,

title = {Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly},

author = {Krzysztof Sobucki and Wojciech Śmigaj and Piotr Graczyk and Maciej Krawczyk and Paweł Gruszecki},

url = {https://doi.org/10.1021/acs.nanolett.3c01592},

doi = {10.1021/acs.nanolett.3c01592},

year  = {2023},

date = {2023-07-31},

urldate = {2023-07-31},

journal = {Nano Letters},

volume = {23},

number = {6979–6984},

issue = {15},

abstract = {We demonstrate numerically how a spin wave (SW) beam obliquely incident on the edge of a thin film placed below a ferromagnetic stripe can excite leaky SWs guided along the stripe. During propagation, leaky waves emit energy back into the layer in the form of plane waves and several laterally shifted parallel SW beams. This resonance excitation, combined with interference effects of the reflected and re-emitted waves, results in the magnonic Wood’s anomaly and a significant increase of the Goos-Hänchen shift magnitude. This yields a unique platform to control SW reflection and transdimensional magnonic router that can transfer SWs from a 2D platform into a 1D guided mode.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevB.108.014418,

title = {Modal approach to modeling spin wave scattering},

author = {Wojciech Śmigaj and Krzysztof Sobucki and Paweł Gruszecki and Maciej Krawczyk},

url = {https://link.aps.org/doi/10.1103/PhysRevB.108.014418},

doi = {10.1103/PhysRevB.108.014418},

year  = {2023},

date = {2023-07-14},

journal = {Phys. Rev. B},

volume = {108},

number = {15},

issue = {1},

pages = {014418},

abstract = {Efficient numerical methods are required for the design of optimized devices. In magnonics, the primary computational tool is micromagnetic simulations, which solve the Landau-Lifshitz equation discretized in time and space. However, their computational cost is high, and the complexity of their output hinders insight into the physics of the simulated system, especially in the case of multimode propagating-wave-based devices. We propose a finite-element modal method allowing an efficient solution of the scattering problem for dipole-exchange spin waves propagating perpendicularly to the magnetization direction. The method gives direct access to the scattering matrix of the whole system and its components. We extend the formula for the power carried by a magnetostatic mode in the Damon-Eshbach configuration to the case with exchange, allowing the scattering coefficients to be normalized to represent the fraction of the input power transferred to each output channel. We apply the method to the analysis of spin wave scattering on a basic functional block of magnonic circuits, consisting of a resonator dynamically coupled to a thin film. The results and the method are validated by comparison with micromagnetic simulations.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Shekhar2023,

title = {Influence of CoFeB layer thickness on elastic parameters in CoFeB/MgO heterostructures},

author = {Shashank Shekhar and Sławomir Mielcarek and Y Otani and Bivas Rana and Aleksandra Trzaskowska},

doi = {10.1038/s41598-023-37808-4},

year  = {2023},

date = {2023-07-01},

urldate = {2023-07-01},

journal = {Scientific Reports },

volume = {13},

issue = {1},

pages = {10668},

abstract = {The surface acoustic waves, i.e., surface phonons may have huge potential for future spintronic devices, if coupled to other waves (e.g., spin waves) or quasiparticles. In order to understand the coupling of acoustic phonons with the spin degree of freedom, especially in magnetic thin film-based heterostructures, one needs to investigate the properties of phonons in those heterostructures. This also allows us to determine the elastic properties of individual magnetic layers and the effective elastic parameters of the whole stacks. Here, we study frequency versus wavevector dispersion of thermally excited SAWs in CoFeB/MgO heterostructures with varying CoFeB thickness by employing Brillouin light spectroscopy. The experimental results are corroborated by finite element method-based simulations. From the best agreement of simulation results with the experiments, we find out the elastic tensor parameters for CoFeB layer. Additionally, we estimate the effective elastic parameters (elastic tensors, Young’s modulus, Poisson’s ratio) of the whole stacks for varying CoFeB thickness. Interestingly, the simulation results, either considering elastic parameters of individual layers or considering effective elastic parameters of whole stacks, show good agreement with the experimental results. These extracted elastic parameters will be very useful to understand the interaction of phonons with other quasiparticles.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevApplied.19.064045,

title = {Spin-Wave Spectral Analysis in Crescent-Shaped Ferromagnetic Nanorods},

author = {Mateusz Gołębiewski and Hanna Reshetniak and Uladzislau Makartsou and Maciej Krawczyk and A van den Berg and S Ladak and A Barman},

url = {https://link.aps.org/doi/10.1103/PhysRevApplied.19.064045},

doi = {10.1103/PhysRevApplied.19.064045},

year  = {2023},

date = {2023-06-14},

journal = {Phys. Rev. Appl.},

volume = {19},

number = {10},

issue = {6},

pages = {064045},

abstract = {The research on the properties of spin waves (SWs) in three-dimensional nanosystems is an innovative idea in the field of magnonics. Mastering and understanding the nature of magnetization dynamics and binding of SWs at surfaces, edges, and in-volume parts of three-dimensional magnetic systems enables the discovery of alternative phenomena and suggests other possibilities for their use in magnonic and spintronic devices. In this work, we use numerical methods to study the effect of geometry and external magnetic field manipulations on the localization and dynamics of SWs in crescent-shaped (CS) waveguides. It is shown that changing the magnetic field direction in these waveguides breaks the symmetry and affects the localization of eigenmodes with respect to the static demagnetizing field. This, in turn, has a direct effect on their frequency. Furthermore, CS structures are found to be characterized by significant saturation at certain field orientations, resulting in a cylindrical magnetization distribution. Thus, we present chirality-based nonreciprocal dispersion relations for high-frequency SWs, which can be controlled by the field direction (shape symmetry) and its amplitude (saturation).},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rana2023,

title = {Anisotropy of magnetic damping in Ta/CoFeB/MgO heterostructures},

author = {Bivas Rana and Y Otani},

doi = {10.1038/s41598-023-35739-8},

year  = {2023},

date = {2023-05-26},

journal = {Scientific Reports},

volume = {13},

issue = {1},

pages = {8532},

abstract = {Magnetic damping controls the performance and operational speed of many spintronics devices. Being a tensor quantity, the damping in magnetic thin films often shows anisotropic behavior with the magnetization orientation. Here, we have studied the anisotropy of damping in Ta/CoFeB/MgO heterostructures, deposited on thermally oxidized Si substrates, as a function of the orientation of magnetization. By performing ferromagnetic resonance (FMR) measurements based on spin pumping and inverse spin Hall effect (ISHE), we extract the damping parameter in those films and find that the anisotropy of damping contains four-fold and two-fold anisotropy terms. We infer that four-fold anisotropy originates from two-magnon scattering (TMS). By studying reference Ta/CoFeB/MgO films, deposited on LiNbO3 substrates, we find that the two-fold anisotropy is correlated with in-plane magnetic anisotropy (IMA) of the films, suggesting its origin as the anisotropy in bulk spin–orbit coupling (SOC) of CoFeB film. We conclude that when IMA is very small, it’s correlation with two-fold anisotropy cannot be experimentally identified. However, as IMA increases, it starts to show a correlation with two-fold anisotropy in damping. These results will be beneficial for designing future spintronics devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{popadiuk2023,

title = {Emergent Magnetic Field and Nonzero Gyrovector of the Toroidal Magnetic Hopfion},

author = {Dariia Popadiuk and Elena Tartakovskaya and Maciej Krawczyk and K Y Guslienko},

url = {https://doi.org/10.1002/pssr.202300131},

year  = {2023},

date = {2023-05-13},

journal = {Rapid Research Letters},

abstract = {Magnetic hopfions are localized magnetic solitons with a nonzero 3D topological

charge (Hopf index). Herein, an analytical calculation of the magnetic hopfion

gyrovector is presented and it is shown that it does not vanish even in an infinite

sample. The calculation method is based on the concept of the emergent

magnetic field. The particular case of the simplest nontrivial toroidal hopfion with

the Hopf index jQHj ¼ 1 in the cylindrical magnetic dot is considered and

dependencies of the gyrovector components on the dot sizes are calculated.

Nonzero hopfion gyrovector is important in any description of the hopfion

dynamics within the collective coordinate Thiele’s approach.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mehta_tuna_23,

title = {Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals},

author = {R Mehta and Mathieu Moalic and Maciej Krawczyk and S Saha},

doi = {10.1088/1361-648X/acd15f},

year  = {2023},

date = {2023-05-12},

urldate = {2023-05-12},

journal = {Journal of Physics: Condensed Matter},

volume = {35},

number = {32},

abstract = {Reprogramming the structure of the magnonic bands during their operation is important for controlling spin waves in magnonic devices. Here, we report the tunability of the spin-wave spectra for a triangular shaped deterministic magnonic fractal, which is known as Sierpinski triangle by solving the Landau–Lifshitz–Gilbert equation using a micromagnetic simulations. The spin-wave dynamics change significantly with the variation of iteration number. A wide frequency gap is observed for a structure with an iteration number exceeding some value and a plenty of mini-frequency bandgaps at structures with high iteration number. The frequency gap could be controlled by varying the strength of the magnetic field. A sixfold symmetry in the frequency gap is observed with the variation of the azimuthal angle of the external magnetic field. The spatial distributions of the spin-wave modes allow to identify the bands surrounding the gap. The observations are important for the application of magnetic fractals as a reconfigurable aperiodic magnonic crystals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{flores2023mid,

title = {Mid-infrared optical properties of non-magnetic-metal/CoFeB/MgO heterostructures},

author = {J M Flores-Camacho and Bivas Rana and R E Balderas-Navarro and A Lastras-Martínez and Y Otani and J Puebla},

doi = {10.1088/1361-6463/acd00f},

year  = {2023},

date = {2023-05-09},

urldate = {2023-05-09},

journal = {Journal of Physics D: Applied Physics},

volume = {56},

number = {31},

abstract = {We report on the optical characterization of non-magnetic metal (NM)/ferromagnetic (Co20Fe60B20)/MgO heterostructures and interfaces by using mid infrared (MIR) spectroscopic ellipsometry at room temperature. We extracted for the MIR range the dielectric function (DF) of Co20Fe60B20, that is lacking in literature, from a multisample analysis. From the optical modeling of the heterostructures we detected and determined the dielectric tensor properties of a two-dimensional electron gas (2DEG) forming at the NM and the CoFeB interface. These properties comprise independent Drude parameters for the in-plane and out-of plane tensor components, with the latter having an epsilon-near-zero frequency within our working spectral range. A feature assigned to spin–orbit coupling (SOC) is identified. Furthermore, it is found that both, the interfacial properties, 2DEG Drude parameters and SOC strength, and the apparent DF of the MgO layer depend on the type of the underlying NM, namely, Pt, W, or Cu. The results reported here should be useful in tailoring novel phenomena in such types of heterostructures by assessing their optical response noninvasively, complementing existing characterization tools such as angle-resolved photoemission spectroscopy, and those related to electron/spin transport.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Serebryannikov:23,

title = {Wide-angle and simultaneously wideband blazing (deflection) enabling multifunctionality in metagratings comprising epsilon-near-zero materials},

author = {Andriy E Serebryannikov and D Skigin and H Hajian and E Ozbay },

url = {https://opg.optica.org/josab/abstract.cfm?URI=josab-40-5-1340},

doi = {10.1364/JOSAB.485457},

year  = {2023},

date = {2023-05-01},

urldate = {2023-05-01},

journal = {Journal of the Optical Society of America B},

volume = {40},

number = {5},

pages = {1340--1349},

abstract = {This paper investigates diffractions by gratings made of a dispersive material in an epsilon-near-zero (ENZ) regime and having one-side corrugations, and those by two-component dielectric-ENZ gratings with the inner corrugations and flat outer interfaces. The goal is to achieve wideband and simultaneously wide-angle -1st order blazing (deflection) that may enable wideband spatial filtering and demultiplexing in reflection mode. Several typical scenarios are discussed, which differ in the maximum magnitude of the blazed wave and size of the blazing area observed on the frequency-incidence angle plane, as well as the contribution of the ranges of positive and negative permittivity in the vicinity of zero. The high capability of ENZ and dielectric-ENZ gratings in asymmetric reflection is demonstrated for three different levels of losses for the dispersive material.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevApplied.19.044087,

title = {Controlling Selection Rules for Magnon Scattering in Nanomagnets by Spatial Symmetry Breaking},

author = {A Etesamirad and Julia Kharlan and R Rodriguez and I Barsukov and R Verba},

url = {https://link.aps.org/doi/10.1103/PhysRevApplied.19.044087},

doi = {10.1103/PhysRevApplied.19.044087},

year  = {2023},

date = {2023-04-27},

urldate = {2023-04-27},

journal = {Physics Review Applied},

volume = {19},

number = {044087},

issue = {4},

pages = {15},

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}

}

@article{PhysRevB.107.134416,

title = {Between waves and patterns: Spin wave freezing in films with Dzyaloshinskii-Moriya interaction},

author = {J Kisielewski and Paweł Gruszecki and Maciej Krawczyk and V Zablotskii and A Maziewski},

doi = {10.1103/PhysRevB.107.134416},

year  = {2023},

date = {2023-04-12},

urldate = {2023-04-12},

journal = {Physical Review B},

volume = {107},

number = {14},

issue = {13},

pages = {134416},

abstract = {The relationship between waves and static pattern formation is an intriguing effect and remains unexplained

in many areas of physics, including magnetism. We study the spin-wave-mediated spin reorientation transition

(SRT) in magnetic films with uniaxial magnetic anisotropy and Dzyaloshinskii-Moriya interaction (DMI). In

particular, we show that propagating spin waves can freeze in the SRT, causing periodic magnetic domains to

arise, which is reminiscent of the wave amplitude distribution. This process can take place under the influence of

a change in the magnetic field, but also of other parameters. Interestingly, at the SRT, DMI nonreciprocity leads

to the emergence of flowing magnetization patterns, which suggests a spontaneous breaking of translational

symmetry, and the formation of magnonic space-time crystals. The described phenomena are general and should

take place in a large family of magnetic materials. Therefore, the results should be of great importance for the

further development of spintronics and magnonics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{deka2023ferromagnetic,

title = {Ferromagnetic resonance excited by interfacial microwave electric field: the role of current-induced torques},

author = {A Deka and Bivas Rana and Y Otani and Y Fukuma},

doi = {10.1088/1361-648X/acc377},

year  = {2023},

date = {2023-03-24},

journal = {Journal of Physics: Condensed Matter},

volume = {35},

number = {21},

pages = {214003},

abstract = {Excitation of magnetization dynamics in magnetic materials, especially in ultrathin

ferromagnetic films, is of utmost importance for developing various ultrafast spintronics

devices. Recently, the excitation of magnetization dynamics, i.e. ferromagnetic resonance

(FMR) via electric field-induced modulation of interfacial magnetic anisotropies, has received

particular attention due to several advantages, including lower power consumption. However,

several additional torques generated by unavoidable microwave current induced because of the

capacitive nature of the junctions may also contribute to the excitation of FMR apart from

electric field-induced torques. Here, we study the FMR signals excited by applying microwave

signal across the metal-oxide junction in CoFeB/MgO heterostructures with Pt and Ta buffer

layers. Analysis of the resonance line shape and angular dependent behavior of resonance

amplitude revealed that apart from voltage-controlled in-plane magnetic anisotropy (VC-IMA)

torque a significant contribution can also arises from spin-torques and Oersted field torques

originating from the flow of microwave current through metal-oxide junction. Surprisingly, the

overall contribution from spin-torques and Oersted field torques are comparable to the VC-IMA

torque contribution, even for a device with negligible defects. This study will be beneficial for

designing future electric field-controlled spintronics devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1063/5.0134099,

title = {Unidirectional spin-wave edge modes in magnonic crystal},

author = {J Feilhauer and Mateusz Zelent and Z Zhang and J Christensen and Michał Mruczkiewicz},

url = { https://doi.org/10.1063/5.0134099},

doi = {10.1063/5.0134099},

year  = {2023},

date = {2023-02-13},

urldate = {2023-02-13},

journal = {APL Materials},

volume = {11},

number = {2},

pages = {021104},

abstract = {We present a numerical demonstration of magnonic crystals hosting unidirectional, topologically protected edge states. The magnonic crystal is formed of dipolarly coupled Permalloy triangles. We show that due to the geometry of the block, the size of the structure can be scaled up. In addition, edge states can be found over a wide frequency range. Experimental detection of edge excitations in the considered system can be done with state-of-the-art techniques. Thus, we demonstrate a proof-of-concept magnonic Chern topological insulator nanostructure with simple geometry feasible for experimental realization. Furthermore, by tuning the strength of the perpendicular magnetic field, we induce a topological phase transition, which results in the change of direction of the topological edge state. Then, we demonstrate the magnonic switch based on this effect.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{10037146,

title = {Mechanically Tunable Topological Transition and High-Directional Propagation of Surface Waves at Bilayer Hyperbolic Metasurfaces},

author = {Liubov Ivzhenko and A Girich and A Hrinchenko and O Yermakov},

doi = {10.1109/UkrMW58013.2022.10037146},

year  = {2023},

date = {2023-02-13},

urldate = {2023-02-13},

journal = {2022 IEEE 2nd Ukrainian Microwave Week (UkrMW)},

pages = {214-217},

abstract = {We propose simple and efficient way to control the propagation regime and direction of spoof surface plasmon-polaritons localized at bilayer hyperbolic metasurfaces. We demonstrate the photonic topological transition at the same frequency implemented with a mutual rotation of the metasurface layers. Finally, we show the tunable multidirectional in-plane canalization of surface waves adjusting by the interlayer coupling. These results discover new opportunities for the manipulation over surface waves at metasurfaces.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{gruszecki_influence_23,

title = {Influence of Dzyaloshinskii–Moriya interaction and perpendicular anisotropy on spin waves propagation in stripe domain patterns and spin spirals},

author = {Paweł Gruszecki and J Kisielewski

},

doi = {https://doi.org/10.1038/s41598-023-28271-2},

year  = {2023},

date = {2023-01-21},

journal = {Scientific Reports},

volume = {13},

number = {1218},

abstract = {Texture-based magnonics focuses on the utilization of spin waves in magnetization textures to process information. Using micromagnetic simulations, we study how (1) the dynamic magnetic susceptibility, (2) dispersion relations, and (3) the equilibrium magnetic configurations in periodic magnetization textures in a ultrathin ferromagnetic film in remanence depend on the values of the Dzyaloshinskii–Moriya interaction and the perpendicular magnetocrystalline anisotropy. We observe that for large Dzyaloshinskii–Moriya interaction values, spin spirals with periods of tens of nanometers are the preferred state; for small Dzyaloshinskii–Moriya interaction values and large anisotropies, stripe domain patterns with over a thousand times larger period are preferable. We observe and explain the selectivity of the excitation of resonant modes by a linearly polarized microwave field. We study the propagation of spin waves along and perpendicular to the direction of the periodicity. For propagation along the direction of the periodicity, we observe a bandgap that closes and reopens, which is accompanied by a swap in the order of the bands. For waves propagating in the perpendicular direction, some modes can be used for unidirectional channeling of spin waves. Overall, our findings are promising in sensing and signal processing applications and explain the fundamental properties of periodic magnetization textures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Moalic_antidot_lattice,

title = {Spin-wave spectra in antidot lattice with inhomogeneous perpendicular magnetic anisotropy},

author = {Mathieu Moalic and Maciej Krawczyk and Mateusz Zelent},

doi = {10.1063/5.0128621},

year  = {2022},

date = {2022-12-01},

urldate = {2022-12-01},

journal = {Journal of Applied Physics},

volume = {132},

pages = {213901 },

abstract = {Magnonic crystals are structures with periodically varied magnetic properties that are used to control collective spin-wave excitations. With micromagnetic simulations, we study spin-wave spectra in a 2D antidot lattice based on a multilayered thin film with perpendicular magnetic anisotropy (PMA). We show that the modification of the PMA near the antidot edges introduces interesting changes to the spin-wave spectra, even in a fully saturated state. In particular, the spectra split into two types of excitations: bulk modes with amplitude concentrated in a homogeneous part of the antidot lattice and edge modes with an amplitude localized in the rims of reduced PMA at the antidot edges. Their dependence on the geometrical or material parameters is distinct, but at resonance conditions fulfilled, we found strong hybridization between bulk and radial edge modes. Interestingly, the hybridization between the fundamental modes in bulk and rim is of magnetostatic origin, but the exchange interactions determine the coupling between higher-order radial rim modes and the fundamental bulk mode of the antidot lattice.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rychly_2022_shaping_sw,

title = {Shaping the spin wave spectra of planar 1D magnonic crystals by the geometrical constraints},

author = {Justyna Rychły and J Walowski and C Denker and T Tubandt and M Münzenberg and Jarosław W Kłos },

doi = {https://doi.org/10.1038/s41598-022-24969-x},

year  = {2022},

date = {2022-11-30},

urldate = {2022-11-30},

journal = {Scientific Reports},

volume = {12},

number = {20678 },

abstract = {We present experimental and numerical studies demonstrating the influence of geometrical parameters on the fundamental spin-wave mode in planar 1D magnonic crystals. The investigated magnonic crystals consist of flat stripes separated by air gaps. The adjustment of geometrical parameters allows tailoring of the spin-wave frequencies. The width of stripes and the width of gaps between them affect spin-wave frequencies in two ways. First, directly by geometrical constraints confining the spin waves inside the stripes. Second, indirectly by spin-wave pinning, freeing the spin waves to a different extent on the edges of stripes. Experimentally, the fundamental spin-wave mode frequencies are measured using an all-optical pump-probe time-resolved magneto-optical Kerr-effect setup. Our studies address the problem of spin-wave confinement and spin-wave dipolar pinning in an array of coupled stripes. We show that the frequency of fundamental mode can be tuned to a large extent by adjusting the width of the stripes and the width of gaps between them.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Serebryannikov:22,

title = {Thermally switchable, bifunctional, scalable, mid-infrared metasurfaces with VO2 grids capable of versatile polarization manipulation and asymmetric transmission},

author = {Andriy E Serebryannikov and A Lakhtakia and E Ozbay},

url = {https://opg.optica.org/ome/abstract.cfm?URI=ome-12-12-4594},

doi = {10.1364/OME.465468},

year  = {2022},

date = {2022-11-16},

journal = {Opt. Mater. Express},

volume = {12},

number = {12},

pages = {4594--4605},

abstract = {We conceptualized three-array scalable bifunctional metasurfaces comprising only three thin strip grids and numerically determined their characteristics in the mid-infrared spectral regime for switchable operation scenarios involving polarization manipulation and related diodelike asymmetric transmission (AT) as one of two functionalities. A few or all of the grids were taken to be made of VO2, a bifunctionality-enabling phase-change material; there are no layers and/or meta-atoms comprising simultaneously both metal and VO2. For each proposed metasurface, two effective structures and, therefore, two different functionalities exist, corresponding to the metallic and insulating phases of VO2. The achieved scenarios of functionality switching significantly depend on the way in which VO2 is incorporated into the metasurface. Switchable bands of polarization manipulation are up to 40 THz wide. The AT band can be modulated when Fabry-Perot (anti-) resonances come into play. Besides, transmission regimes with the cross-polarized component insensitive to VO2 phase change are possible, as well as the ones with all co- and cross-polarized components having the same magnitude for both linear polarizations of the incident wave.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ivzhenko_2022_manipulation,

title = {Manipulation Over Surface Waves in Bilayer Hyperbolic Metasurfaces: Topological Transition and Multidirectional Canalization},

author = {A Girich and Liubov Ivzhenko and A Hrinchenko and S Tarapov and O Yermakov},

doi = {10.1109/LMWC.2022.3215016},

year  = {2022},

date = {2022-10-27},

urldate = {2022-10-27},

journal = {IEEE Microwave and Wireless Components Letters},

pages = {1 - 4},

abstract = {Spoof surface plasmon-polariton is a type of surface wave (SW) propagating at the artificially engineered structures in microwave and terahertz ranges. These SWs are highly important in planar photonic and on-chip devices, integrated circuits, lenses, sensors, and antennas applications. However, it is still a challenge to control the propagation regime of such SWs including the wavefront shapes and propagation directions. In this letter, we study the SWs in bilayer hyperbolic metasurfaces and show that the interplay between two layers allows them to manage their regime of propagation. We demonstrate the switching between the angle and number of propagation directions of SWs at the same frequency. Finally, we demonstrate experimentally the tunable multidirectional in-plane canalization of SWs by adjusting the directions of their propagation within the angular range from 0 ∘ to 12.8 ∘ . The discovered rotation-mediated interlayer coupling of hyperbolic metasurfaces paves the way toward efficient in-plane transfer of localized electromagnetic signals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{bivas_2022,

title = {Pattern recognition with neuromorphic computing using magnetic field–induced dynamics of skyrmions},

author = {T Yokouchi and S Sugimoto and Bivas Rana and S Seki and N Ogawa and Y Shiomi and S Kasai and Y Otani },

doi = {10.1126/sciadv.abq5652},

year  = {2022},

date = {2022-09-30},

journal = {Science Advances},

volume = {8},

issue = {39},

abstract = {Nonlinear phenomena in physical systems can be used for brain-inspired computing with low energy consumption. Response from the dynamics of a topological spin structure called skyrmion is one of the candidates for such a neuromorphic computing. However, its ability has not been well explored experimentally. Here, we experimentally demonstrate neuromorphic computing using nonlinear response originating from magnetic field–induced dynamics of skyrmions. We designed a simple-structured skyrmion-based neuromorphic device and succeeded in handwritten digit recognition with the accuracy as large as 94.7% and waveform recognition. Notably, there exists a positive correlation between the recognition accuracy and the number of skyrmions in the devices. The large degrees of freedom of skyrmion systems, such as the position and the size, originate from the more complex nonlinear mapping, the larger output dimension, and, thus, high accuracy. Our results provide a guideline for developing energy-saving and high-performance skyrmion neuromorphic computing devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{magnon_spectrum,

title = {Magnon spectrum of Bloch hopfion beyond ferromagnetic resonance},

author = {Krzysztof Sobucki and Maciej Krawczyk and Elena Tartakovskaya and Piotr Graczyk},

url = { https://doi.org/10.1063/5.0100484},

year  = {2022},

date = {2022-09-08},

journal = {APL Materials},

volume = {10},

number = {9},

pages = {091103},

abstract = {With the development of new nanofabrication technologies and measurement techniques, the interest of researchers is moving toward 3D structures and 3D magnetization textures. Special attention is paid to the topological magnetization textures, particularly hopfions. In this paper, we investigate the magnetization dynamics of the hopfion through the numerical solution of the eigenvalue problem. We show that the spectrum of spin-wave modes of the hopfion is much richer than those attainable in ferromagnetic resonance experiments or time-domain simulations reported so far. We identified four groups of modes that differ in the character of oscillations (clockwise or counter-clockwise rotation sense), the position of an average amplitude localization along the radial direction, and different oscillations in the vertical cross section. The knowledge of the full spin-wave spectrum shall help in hopfion identification, understanding of the interaction between spin waves and hopfion dynamics as well as the development of the potential of hopfion in spintronic and magnonic applications.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{doi:10.1063/5.0100594,

title = {Scattering of spin waves in a multimode waveguide under the influence of confined magnetic skyrmion},

author = {Katarzyna Kotus and Mathieu Moalic and Mateusz Zelent and Maciej Krawczyk and Paweł Gruszecki},

url = {https://doi.org/10.1063/5.0100594},

doi = {10.1063/5.0100594},

year  = {2022},

date = {2022-09-08},

journal = {APL Materials},

volume = {10},

number = {9},

pages = {091101},

abstract = {Nontrivial magnetization textures, such as skyrmions, have become a driving force in the physics of magnetism. Furthermore, the utilization of magnetization textures is fueling the development of magnon-based technologies that could provide beyond-CMOS solutions. Here, using a self-developed spin wave (SW) excitation scheme, we selectively excite specific modes and investigate the scattering of SWs on nanodot hosting a Néel-type skyrmion and placed above a multimode waveguide. In particular, at low frequencies, we observe significant reflections from the imprint induced by the skyrmion upon the waveguide. As the frequency increases, the transmission increases as well; however, it is accompanied by scattering to other types of modes. Here, we observe a direct contribution of the skyrmion to the scattering process and various types of conversions of the incident SW modes into other modes quantized by width for both reflected and transmitted SWs. The utilization of imprinted magnetization textures in nonplanar systems to control SW flow can open new possibilities for developing SW-based circuits for ultralow-power signal processing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Szulc_Reconfigurable_Magnonic_Crystals,

title = {Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers},

author = {Krzysztof Szulc and S Tacchi and A Hirreo-Rodríguez and J Díaz and Paweł Gruszecki and Piotr Graczyk and and C Quirós and D Markó and J I Martín and M Vélez and D S Schmool and G Carlotti and Maciej Krawczyk and L M Álvarez-Prado},

doi = {https://doi.org/10.1021/acsnano.2c04256},

year  = {2022},

date = {2022-08-31},

journal = {ACS Nano},

abstract = {Reconfigurable magnetization textures offer control of spin waves with promising properties for future low-power beyond-CMOS systems. However, materials with perpendicular magnetic anisotropy (PMA) suitable for stable magnetization-texture formation are characterized by high damping, which limits their applicability in magnonic devices. Here, we propose to overcome this limitation by using hybrid structures, i.e., a PMA layer magnetostatically coupled to a low-damping soft ferromagnetic film. We experimentally show that a periodic stripe-domain texture from a PMA layer is imprinted upon the soft layer and induces a nonreciprocal dispersion relation of the spin waves confined to the low-damping film. Moreover, an asymmetric bandgap features the spin-wave band diagram, which is a clear demonstration of collective spin-wave dynamics, a property characteristic for magnonic crystals with broken time-reversal symmetry. The composite character of the hybrid structure allows for stabilization of two magnetic states at remanence, with parallel and antiparallel orientation of net magnetization in hard and soft layers. The states can be switched using a low external magnetic field; therefore, the proposed system obtains an additional functionality of state reconfigurability. This study offers a link between reconfigurable magnetization textures and low-damping spin-wave dynamics, providing an opportunity to create miniaturized, programmable, and energy-efficient signal processing devices operating at high frequencies.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{SZAFRANSKI2022110893,

title = {Above-room-temperature ferroelectricity and piezoelectric activity of dimethylglycinium-dimethylglycine chloride},

author = {M Szafrański and Zbigniew Tylczyński and M Wiesner and P Czarnecki and V V Ghazaryan and A M Petrosyan},

url = {https://www.sciencedirect.com/science/article/pii/S0264127522005159},

doi = {https://doi.org/10.1016/j.matdes.2022.110893},

issn = {0264-1275},

year  = {2022},

date = {2022-08-27},

journal = {Materials & Design},

volume = {220},

pages = {110893},

abstract = {Heavy-metal-free ferroelectrics are sought as environmentally compatible alternatives to commonly used inorganic oxides. Here, we demonstrate direct evidence of the ferroelectric properties of a hybrid organic–inorganic material, dimethylglycinium-dimethylglycine chloride. At room temperature, the compound crystallizes in the polar space group P21 and exhibits a switchable spontaneous polarization of 1.9 μC cm−2. Ferroelectric properties are preserved in a wide temperature range up to about 401 K, where the crystal undergoes the transition to the paraelectric phase of the space group P21/c. The temperature-dependent single-crystal X-ray diffraction study and the calorimetric data indicate an order–disorder contribution to the transition mechanism, which is consistent with the critical slowing down of the dielectric relaxation observed near the Curie point. The spontaneous polarization results from ionic displacements that are induced by changes in the disordering of the dimeric cations. In the ferroelectric phase, the crystal exhibits remarkable piezoelectric activity. The electromechanical and elastic properties of the material were thoroughly characterized.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{PhysRevB.106.064430,

title = {Spin-wave localization on phasonic defects in a one-dimensional magnonic quasicrystal},

author = {Szymon Mieszczak and Maciej Krawczyk and Jarosław W Kłos},

url = {https://link.aps.org/doi/10.1103/PhysRevB.106.064430},

doi = {10.1103/PhysRevB.106.064430},

year  = {2022},

date = {2022-08-25},

journal = {Phys. Rev. B},

volume = {106},

number = {10},

issue = {6},

pages = {064430},

abstract = {We report on the evolution of the spin-wave spectrum under structural disorder introduced intentionally into a one-dimensional magnonic quasicrystal. We study theoretically a system composed of ferromagnetic strips arranged in a Fibonacci sequence. We considered several stages of disorder in the form of phasonic defects, where different rearrangements of strips are introduced. By transition from the quasiperiodic order towards disorder, we show a gradual degradation of spin-wave fractal spectra and closing of the frequency gaps. In particular, the phasonic defects lead to the disappearance of the van Hove singularities at the frequency gap edges by moving modes into the frequency gaps and creating new modes inside the frequency gaps. These modes disperse and eventually can close the gap, with increasing disorder levels. The work reveals how the presence of disorder modifies the intrinsic spin-wave localization existing in undefected magnonic quasicrystals. The paper contributes to the knowledge of magnonic Fibonacci quasicrystals and opens the way to study of the phasonic defects in two-dimensional magnonic quasicrystals.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{golkebiewski2022self,

title = {Self-Imaging Based Programmable Spin-Wave Lookup Tables},

author = {Mateusz Gołębiewski and Paweł Gruszecki and Maciej Krawczyk

},

doi = {https://doi.org/10.1002/aelm.202200373},

year  = {2022},

date = {2022-07-21},

urldate = {2022-07-21},

journal = {Advanced Electronic Materials},

pages = {2200373},

abstract = {Inclusion of spin waves into the computing paradigm, where complementary metal-oxide-semiconductor devices are still at the fore, is now a challenge for scientists around the world. In this work, a wave phenomenon that has not yet been used in magnonics-self-imaging, also known as the Talbot effect, to design and simulate the operation of interference systems that perform logic functions on spin waves in thin ferromagnetic multimode waveguides is utilized. Lookup tables operating in this way are characterized by high programmability and scalability; thanks to which they are promising for their implementation in field-programmable gate arrays circuits, where multiple logic realizations can be obtained.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{pandarole,

title = {Role of Spin-Orbit Coupling on Ultrafast Spin Dynamics in Nonmagnet/Ferromagnet Heterostructures},

author = {S N Panda and Bivas Rana and Y Otani and A Barman},

doi = {10.1002/qute.202200016},

year  = {2022},

date = {2022-07-10},

journal = {Advanced Quantum Technologies},

pages = {2200016},

abstract = {Spin–orbit coupling (SOC), the interaction between spin and orbital angular momentum of electrons, is imperative to control magnetic properties of nonmagnet (NM)/ferromagnet (FM) heterostructures and design energy-efficient and faster spin-based devices. Here, femtosecond pulsed laser-induced time-resolved magneto-optical Kerr effect magnetometry is employed to investigate magnetization dynamics in different NM/Co20Fe60B20 heterostructures, where the NM layer varies as Cu, Ta, W, Pt, Ta/Ru/Ta, and Si/SiO2 (no underlayer) that differ in SOC strength. It is observed that there is a systematic variation in ultrafast demagnetization time (τm), fast remagnetization time (τr), and Gilbert damping parameter (α) with the SOC strength of the underlayer and an inverse relationship between α and τm, τr is established due to the dominant contribution of spin current transport in ultrafast demagnetization and fast remagnetization processes. The spin pumping formalism estimates the effective spin-mixing conductance (Geff) for different interfaces, which signifies that the high SOC strength of underlayers results in high Geff indicating more efficient transport of spin current through it. This study suggests that the SOC strength of the NM underlayer plays a significant role in controlling the ultrafast demagnetization process through interfacial spin current transport in a NM/FM heterostructure which can be beneficial for the development of ultrafast spintronics devices.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{mieszczak_interface_2022,

title = {Interface modes in planar one-dimensional magnonic crystals},

author = {Szymon Mieszczak and Jarosław W Kłos},

url = {https://www.nature.com/articles/s41598-022-15328-x},

doi = {10.1038/s41598-022-15328-x},

issn = {2045-2322},

year  = {2022},

date = {2022-07-05},

urldate = {2022-07-05},

journal = {Scientific Reports},

volume = {12},

number = {1},

pages = {11335},

abstract = {We present the concept of Zak phase for spin waves in planar magnonic crystals and discuss the existence condition of interface modes localized on the boundary between two magnonic crystals with centrosymmetric unit cells. Using the symmetry criterion and analyzing the logarithmic derivative of the Bloch function, we study the interface modes and demonstrate the bulk-to-edge correspondence. Our theoretical results are verified numerically and extended to the case in which one of the magnonic crystals has a non-centrosymmetric unit cells. We show that by shifting the unit cell, the interface modes can traverse between the band gap edges. Our work also investigate the role of the dipolar interaction, by comparison the systems both with exchange interaction only and combined dipolar-exchange interactions.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{serebryannikov2022multifunctional,

title = {Multifunctional blazed gratings for multiband spatial filtering, retroreflection, splitting, and demultiplexing based on C2 symmetric photonic crystals},

author = {Andriy E Serebryannikov and D Skigin and G Vandenbosch and E Ozbay },

doi = {https://doi.org/10.1063/5.0093989},

year  = {2022},

date = {2022-06-09},

journal = {Journal of Applied Physics},

volume = {131},

number = {22},

pages = {223101},

abstract = {The concept of multifunctional reflection-mode gratings that are based on rod-type photonic crystals (PhCs) with C2 symmetry is

introduced. The specific modal properties lead to the vanishing dependence of the first-negative-order maximum on the angle of incidence

and the nearly sinusoidal redistribution of the incident-wave energy between zero order (specular reflection) and first negative

diffraction order (deflection) at frequency variation. These features are key enablers of diverse functionalities and the merging of different

functionalities into one structure. The elementary functionalities, of which multifunctional scenarios can be designed, include

but are not restricted to multiband spatial filtering, multiband splitting, retroreflection, and demultiplexing. The proposed structures

are capable of multifunctional operation in the case of a single polychromatic incident wave or multiple mono-/polychromatic waves

incident at different angles. The generalized demultiplexing is possible in the case of several polychromatic waves. The aforementioned

deflection properties yield merging demultiplexing with splitting in one functionality. In turn, it may contribute to more complex

multifunctional scenarios. Finally, the proposed PhC gratings are studied in transmissive configuration, in which they show some

unusual properties.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{TrzaskowskaMechanical2022,

title = {Mechanical properties of the mouse femur after treatment with diclofenac and running exercises},

author = {Aleksandra Trzaskowska and Sławomir Mielcarek and T Lehmann and E Pruszyńska-Oszmałek and P Kołodziejski and M Głowacki},

url = {https://www.actabio.pwr.wroc.pl/Vol24No2/33.pdf},

year  = {2022},

date = {2022-05-26},

journal = {Acta of Bioengineering and Biomechanics},

volume = {24},

number = {2},

abstract = {The flexible properties of the bone are essential for the movement and protection of vital organs. The ability of a bone to

resist fractures under the influence of large muscles and physical activity depends on its established mechanical properties. This article

discusses how exercise such as treadmill running and taking non-steroidal anti-inflammatory drugs (NSAIDs), such as diclofenac, affect

the musculoskeletal system by modifying the elastic and thermal properties of the left femur of a mouse. Methods: The research was

conducted using 9-week-old C57BL/6J female mice. In order to investigate the elastic and thermal properties of bones, dynamic mechanical

analysis (DMA) and differential scanning calorimetry (DSC) were performed. Results: The study of elastic properties, followed

by in-depth statistical analysis, shows that taking diclofenac slightly reduces the elastic parameters of the bones under study. These

changes are more pronounced in DSC studies, the shift of the observed endothermic peaks is on the order of several degrees with a simultaneous

increase in the enthalpy of this process. Conclusions: The opposite effect of the applied factors – diclofenac and running – on

the elastic properties of the bones of the examined mice was found. The external factors – running and diclofenac – modify the basic

parameters of the endothermic process associated with the release of water.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}