Prof. dr hab. Maciej Krawczyk

Prof. dr hab. Maciej Krawczyk

Department of Physics of Nanostructures

Tel: +48 61 829 5060
Loc: wing G, second floor, room 277
Email: krawczyk@amu.edu.pl

Scientific degrees

Title of professor – 2015
Habilitation – 2009
PhD in Physics – 2001

Research interests

Keywords: magnonics, metamaterials, metasurfaces, nanomagnetism, magnetization dynamics, magnetoelastic

The research is focused on studies in the field of magnonics, but cover also phononics, photonics, magnetoelastic and metamaterial physics. The interest cover a broad spectra of wave-dynamic effects in nanostructures, including:

Band structure formation for spin, electromagnetic and elastic waves in artificial crystals;
Control of the wave propagation by the nano-structuralization and interactions;
Study of the coupling between the waves of different types;
Nonreciprocity in wave propagation;
Magnetization dynamics in complex magnetization textures;
Metamaterials and metasurfaces;
Application of the spin waves.

Other information

PI of the UE projects:

„DYNAMAG: Advanced computational studies of dynamic phenomena in magnetic Nano-materials”, nr CP FP 233552; (2009-2012), (FP7-NMP-2008-EU-India-2);
„MAGNONICS: Mastering magnons in magnetic meta materials”, nr: CP-FP 228673; 7PR UE Cooperation Theme, NMP (2009-2012);
„NoWaPhen – Novel wave phenomena in magnetic nanostructures”, nr: 247556; 7PR UE People Marie Curie Actions (2010-2014), GA. 247556 FP7-PEOPLE-2009-IRSES;
„MagIC – Magnonics, Interactions and Complexity: a multifunctional aspects of spin wave dynamics”, Horyzont2020, MSCA-RISE-2014: Marie Skłodowska-Curie Research and Innovation Staff Exchange (RISE), GA no. 644348, (2015-2019).

Projects

Maciej Krawczyk

Guidance, control, and amplification of signals in strongly coupled electromagnetic-magnonic systems

2021 - 2025, (NCN OPUS-LAP, No. 2020/39/I/ST3/02413, budget: 1 071 681 PLN).

BibTeX

Maciej Krawczyk

New platform for study wave phenomenon – reconfigurable topological properties and frustrated ground states in magnonics

2021 - 2025, (NCN OPUS 19, No. 2020/37/B/ST3/03936, budget: 2 062 440 PLN).

Links | BibTeX

Maciej Krawczyk

SpinSky – Spin waves in magnetic skyrmionic crystals

2019 - 2022, (NCN Sheng, No. 2018/30/Q/ST3/00416, budget: 999 520,00 PLN).

Links | BibTeX

Publications

2025
48.	Mateusz Gołębiewski, Krzysztof Szulc, Maciej Krawczyk Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures Acta Materialia, 283 , pp. 120499, 2025, ISSN: 1359-6454. Abstract \| Links \| BibTeX @article{GOLEBIEWSKI2025120499, title = {Magnetic field controlled surface localization of ferromagnetic resonance modes in 3D nanostructures}, author = {Mateusz Gołębiewski and Krzysztof Szulc and Maciej Krawczyk}, url = {https://www.sciencedirect.com/science/article/pii/S1359645424008486}, doi = {https://doi.org/10.1016/j.actamat.2024.120499}, issn = {1359-6454}, year = {2025}, date = {2025-01-15}, journal = {Acta Materialia}, volume = {283}, pages = {120499}, abstract = {By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close By extending the current understanding and use of magnonics beyond conventional planar systems, we demonstrate the surface localization of ferromagnetic resonance (FMR) modes through the design of complex three-dimensional nanostructures. Using micromagnetic simulations, we systematically investigate woodpile-like scaffolds and gyroids — periodic chiral entities characterized by their triple junctions. The study highlights the critical role of demagnetizing fields and exchange energy in determining the FMR responses of 3D nanosystems, especially the strongly asymmetric distribution of the spin-wave mode over the system’s height. Importantly, the top–bottom dynamic switching of the surface mode localization across the structures in response to changes in magnetic field orientation provides a new method for controlling magnetization dynamics. The results demonstrate the critical role of the geometric features in dictating the dynamic magnetic behavior of three-dimensional nanostructures, paving the way for both experimental exploration and practical advances in 3D magnonics. Close https://www.sciencedirect.com/science/article/pii/S1359645424008486 doi:https://doi.org/10.1016/j.actamat.2024.120499 Close
2024
47.	P Graczyk, Bivas Rana, Aleksandra Trzaskowska, B K Mahato, Jarosław W. Kłos, Maciej Krawczyk, A Barman Optical excitation and detection of high-frequency Sezawa modes in Si/SiO2 system decorated with Ni80Fe20 nanodot arrays Ultrasonics, 148 , pp. 107522, 2024, ISSN: 0041-624X. Abstract \| Links \| BibTeX @article{GRACZYK2025107522, title = {Optical excitation and detection of high-frequency Sezawa modes in Si/SiO2 system decorated with Ni80Fe20 nanodot arrays}, author = {P Graczyk and Bivas Rana and Aleksandra Trzaskowska and B K Mahato and Jarosław W. Kłos and Maciej Krawczyk and A Barman}, url = {https://www.sciencedirect.com/science/article/pii/S0041624X24002853}, doi = {https://doi.org/10.1016/j.ultras.2024.107522}, issn = {0041-624X}, year = {2024}, date = {2024-12-04}, journal = {Ultrasonics}, volume = {148}, pages = {107522}, abstract = {Surface acoustic waves have emerged as one of the potential candidates for the development of next-generation wave-based information and computing technologies. For practical devices, it is essential to develop the excitation techniques for different types of surface acoustic waves, especially at higher microwave frequencies, and to tailor their frequency versus wave vector characteristics. We show that this can be done by using ultrashort laser pulses incident on the surface of a multilayer decorated with a periodic array of metallic nanodots. Specifically, we study surface acoustic waves in the dielectric substrate Si/SiO2 decorated with a square lattice of thin Ni80Fe20 (Py) dots. Using a femtosecond laser-based optical pump–probe measurement, we detect a number of high-frequency phononic modes. By performing finite element simulations, we identify them as Sezawa modes from the second and third Brillouin zone in addition to the modes confined within the Py dots. The frequency of the Sezawa modes strongly depends on the period of the Py dots and varies in the range between 5 to 15 GHz. Both types of waves cover the same frequency range for Py dots with period less than 400 nm, providing a promising system for magnetoelastic studies.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Surface acoustic waves have emerged as one of the potential candidates for the development of next-generation wave-based information and computing technologies. For practical devices, it is essential to develop the excitation techniques for different types of surface acoustic waves, especially at higher microwave frequencies, and to tailor their frequency versus wave vector characteristics. We show that this can be done by using ultrashort laser pulses incident on the surface of a multilayer decorated with a periodic array of metallic nanodots. Specifically, we study surface acoustic waves in the dielectric substrate Si/SiO2 decorated with a square lattice of thin Ni80Fe20 (Py) dots. Using a femtosecond laser-based optical pump–probe measurement, we detect a number of high-frequency phononic modes. By performing finite element simulations, we identify them as Sezawa modes from the second and third Brillouin zone in addition to the modes confined within the Py dots. The frequency of the Sezawa modes strongly depends on the period of the Py dots and varies in the range between 5 to 15 GHz. Both types of waves cover the same frequency range for Py dots with period less than 400 nm, providing a promising system for magnetoelastic studies. Close https://www.sciencedirect.com/science/article/pii/S0041624X24002853 doi:https://doi.org/10.1016/j.ultras.2024.107522 Close
46.	Ryszard Gieniusz, Paweł Gruszecki, Jan Kisielewski, Anuj Kumar Dhiman, Michal Matczak, Zbigniew Kurant, Iosif Sveklo, Urszula Guzowska, Maria Tekielak, Maciej Krawczyk, Feliks Stobiecki, Andrzej Maziewski Spin wave frequency hysteresis in Ir/Co/Pt multilayers with Dzyaloshinskii-Moriya interaction Phys. Rev. B, 110 , pp. 184410, 2024. Links \| BibTeX @article{PhysRevB.110.184410, title = {Spin wave frequency hysteresis in Ir/Co/Pt multilayers with Dzyaloshinskii-Moriya interaction}, author = {Ryszard Gieniusz and Paweł Gruszecki and Jan Kisielewski and Anuj Kumar Dhiman and Michal Matczak and Zbigniew Kurant and Iosif Sveklo and Urszula Guzowska and Maria Tekielak and Maciej Krawczyk and Feliks Stobiecki and Andrzej Maziewski}, url = {https://link.aps.org/doi/10.1103/PhysRevB.110.184410}, doi = {10.1103/PhysRevB.110.184410}, year = {2024}, date = {2024-11-14}, journal = {Phys. Rev. B}, volume = {110}, pages = {184410}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevB.110.184410 doi:10.1103/PhysRevB.110.184410 Close
45.	Sreedevi Janardhanan, Maciej Krawczyk, Aleksandra Trzaskowska Spin-Wave Dynamics in Ultra-thin Ferromagnetic Films, Patterned, and Non-patterned Bandyopadhyay, Supriyo, Barman, Anjan (Ed.): Nanomagnets as Dynamical Systems: Physics and Applications, pp. 33–69, Springer Nature Switzerland, Cham, 2024, ISBN: 978-3-031-73191-4. Abstract \| Links \| BibTeX @inbook{Janardhanan2024b, title = {Spin-Wave Dynamics in Ultra-thin Ferromagnetic Films, Patterned, and Non-patterned}, author = {Sreedevi Janardhanan and Maciej Krawczyk and Aleksandra Trzaskowska}, editor = {Supriyo Bandyopadhyay and Anjan Barman}, url = {https://doi.org/10.1007/978-3-031-73191-4_2}, doi = {10.1007/978-3-031-73191-4_2}, isbn = {978-3-031-73191-4}, year = {2024}, date = {2024-11-10}, booktitle = {Nanomagnets as Dynamical Systems: Physics and Applications}, pages = {33--69}, publisher = {Springer Nature Switzerland}, address = {Cham}, abstract = {Exploring spin-waveSpin wave (SW) dynamics opens new avenues for technological applications across various fields. This chapter provides a comprehensive review of spin-waveSpin wave (SW) dynamics in both patterned and non-patterned ferromagnetic thin films, and emphasizes the significance of perpendicular magnetic anisotropyPerpendicular magnetic anisotropy (PMA) in this context as well. The chapter begins with an overview of the basic concept and relevance of spin wavesSpin wave (SW), followed by a detailed discussion of Brillouin light scatteringBrillouin light scattering (BLS) methodology. We explore the unique properties of spin wavesSpin wave (SW) in patterned films, such as magnonic crystalsMagnonic crystals (MC), and a comparative study with the behaviour in continuous films has been presented in detail. The future perspective from technological point of view of spin-wave research is vast, ranging from high-frequency data transmission to quantum information processing. Here we highlighted applications encompass spin-wave logic devices, magnonic waveguide, quantum computingSpin wave computing, and the role of spin wavesSpin wave (SW) in the development of novel materials with tailored magnetic properties. Finally, this review addresses the challenges associated with achieving precise control over spin-waveSpin wave (SW) propagation, elucidating spin-waveSpin wave (SW) interactions at the nanoscale, and integrating spin-waveSpin wave (SW) technology with existing technological frameworks.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Close Exploring spin-waveSpin wave (SW) dynamics opens new avenues for technological applications across various fields. This chapter provides a comprehensive review of spin-waveSpin wave (SW) dynamics in both patterned and non-patterned ferromagnetic thin films, and emphasizes the significance of perpendicular magnetic anisotropyPerpendicular magnetic anisotropy (PMA) in this context as well. The chapter begins with an overview of the basic concept and relevance of spin wavesSpin wave (SW), followed by a detailed discussion of Brillouin light scatteringBrillouin light scattering (BLS) methodology. We explore the unique properties of spin wavesSpin wave (SW) in patterned films, such as magnonic crystalsMagnonic crystals (MC), and a comparative study with the behaviour in continuous films has been presented in detail. The future perspective from technological point of view of spin-wave research is vast, ranging from high-frequency data transmission to quantum information processing. Here we highlighted applications encompass spin-wave logic devices, magnonic waveguide, quantum computingSpin wave computing, and the role of spin wavesSpin wave (SW) in the development of novel materials with tailored magnetic properties. Finally, this review addresses the challenges associated with achieving precise control over spin-waveSpin wave (SW) propagation, elucidating spin-waveSpin wave (SW) interactions at the nanoscale, and integrating spin-waveSpin wave (SW) technology with existing technological frameworks. Close https://doi.org/10.1007/978-3-031-73191-4_2 doi:10.1007/978-3-031-73191-4_2 Close
44.	Anuj K Dhiman, Nikodem Leśniewski, Ryszard Gieniusz, Jan Kisielewski, Piotr Mazalski, Zbigniew Kurant, Michał Matczak, Feliks Stobiecki, Maciej Krawczyk, Artem Lynnyk, Andrzej Maziewski, Paweł Gruszecki Reconfigurable magnonic crystals: Spin wave propagation in Pt/Co multilayer in saturated and stripe domain phase APL Materials, 12 (11), pp. 111106, 2024, ISSN: 2166-532X. Abstract \| Links \| BibTeX @article{10.1063/5.0227380, title = {Reconfigurable magnonic crystals: Spin wave propagation in Pt/Co multilayer in saturated and stripe domain phase}, author = {Anuj K Dhiman and Nikodem Leśniewski and Ryszard Gieniusz and Jan Kisielewski and Piotr Mazalski and Zbigniew Kurant and Michał Matczak and Feliks Stobiecki and Maciej Krawczyk and Artem Lynnyk and Andrzej Maziewski and Paweł Gruszecki}, url = {https://doi.org/10.1063/5.0227380}, doi = {10.1063/5.0227380}, issn = {2166-532X}, year = {2024}, date = {2024-11-04}, journal = {APL Materials}, volume = {12}, number = {11}, pages = {111106}, abstract = {To control the spin wave (SW) propagation, external energy sources such as magnetic fields, electric currents, or complex nanopatterning are used, which can be challenging at the deep nanoscale level. In this work, we overcome such limitations by demonstrating SW propagation in Pt/Co multilayers at a remanent state controlled by stripe domain patterns, using Brillouin light scattering and micromagnetic simulations. We show that parallel stripes with a periodicity around 100 nm exhibit reconfigurability, as the stripes can be rotated by applying the in-plane field without damaging their shape. This allows us to study SW propagation perpendicular and parallel to the stripes. We observe multimodal SW spectra—three bands in perpendicular and five in parallel geometry. Numerical results allow us to identify all observed modes and to explain the differences between two configurations by the unequal contribution of all three magnetization components in the SW dynamics. We find that the experimentally measured non-reciprocal dispersion (for the wavevector perpendicular to the stripes) is not the breaking of time-symmetry but the asymmetry in intensity of the measured signals of two different low-frequency modes, which is due to the inhomogeneous SW amplitude distribution over the multilayer thickness and the limited light penetration depth. Our results pave the way for easy reprogrammability and high energy efficiency in nanomagnonics.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close To control the spin wave (SW) propagation, external energy sources such as magnetic fields, electric currents, or complex nanopatterning are used, which can be challenging at the deep nanoscale level. In this work, we overcome such limitations by demonstrating SW propagation in Pt/Co multilayers at a remanent state controlled by stripe domain patterns, using Brillouin light scattering and micromagnetic simulations. We show that parallel stripes with a periodicity around 100 nm exhibit reconfigurability, as the stripes can be rotated by applying the in-plane field without damaging their shape. This allows us to study SW propagation perpendicular and parallel to the stripes. We observe multimodal SW spectra—three bands in perpendicular and five in parallel geometry. Numerical results allow us to identify all observed modes and to explain the differences between two configurations by the unequal contribution of all three magnetization components in the SW dynamics. We find that the experimentally measured non-reciprocal dispersion (for the wavevector perpendicular to the stripes) is not the breaking of time-symmetry but the asymmetry in intensity of the measured signals of two different low-frequency modes, which is due to the inhomogeneous SW amplitude distribution over the multilayer thickness and the limited light penetration depth. Our results pave the way for easy reprogrammability and high energy efficiency in nanomagnonics. Close https://doi.org/10.1063/5.0227380 doi:10.1063/5.0227380 Close
43.	Piotr Graczyk, Maria Pugaczowa-Michalska, Maciej Krawczyk Generation of femtosecond spin-polarized current pulses at Fe/MgO interface by quasi-static voltage Physica E: Low-dimensional Systems and Nanostructures, 165 , pp. 116120, 2024, ISSN: 1386-9477. Abstract \| Links \| BibTeX @article{GRACZYK2025116120, title = {Generation of femtosecond spin-polarized current pulses at Fe/MgO interface by quasi-static voltage}, author = {Piotr Graczyk and Maria Pugaczowa-Michalska and Maciej Krawczyk}, url = {https://www.sciencedirect.com/science/article/pii/S1386947724002248}, doi = {https://doi.org/10.1016/j.physe.2024.116120}, issn = {1386-9477}, year = {2024}, date = {2024-10-03}, journal = {Physica E: Low-dimensional Systems and Nanostructures}, volume = {165}, pages = {116120}, abstract = {The generation of short spin-current pulses is essential for fast spintronic devices. So far, spin current pulses are generated by femtosecond laser pulses which drive spins from a ferromagnetic metal layer. However, the need for miniaturization, simplicity and energy efficiency favour electric-field control of spintronic devices over optic or thermal control. Here, we combine ab initio calculations of electronic density of states at MgO/Fe interface with continuous model for charge transport to investigate the dynamics of the spin-dependent potential. We demonstrate that the voltage-driven instability of the electronic band structure due to the electronic resonant states at the Fe/MgO interface results in the generation of the femtosecond spin-polarized current pulse with the spin polarization up to P=7 00 % that propagates from the interface to the bulk. The dynamics of the current pulses driven by the Stoner instability depends neither on the dielectric relaxation time nor on the details of how the instability is achieved by changing the voltage, i.e. as long as the voltage changes are slow (quasi-static) with respect to the time determined by the spin diffusion constant, being of the order of fs. The presence of the instability can be detected by THz time-domain spectroscopy or pump-probe techniques.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The generation of short spin-current pulses is essential for fast spintronic devices. So far, spin current pulses are generated by femtosecond laser pulses which drive spins from a ferromagnetic metal layer. However, the need for miniaturization, simplicity and energy efficiency favour electric-field control of spintronic devices over optic or thermal control. Here, we combine ab initio calculations of electronic density of states at MgO/Fe interface with continuous model for charge transport to investigate the dynamics of the spin-dependent potential. We demonstrate that the voltage-driven instability of the electronic band structure due to the electronic resonant states at the Fe/MgO interface results in the generation of the femtosecond spin-polarized current pulse with the spin polarization up to P=7 00 % that propagates from the interface to the bulk. The dynamics of the current pulses driven by the Stoner instability depends neither on the dielectric relaxation time nor on the details of how the instability is achieved by changing the voltage, i.e. as long as the voltage changes are slow (quasi-static) with respect to the time determined by the spin diffusion constant, being of the order of fs. The presence of the instability can be detected by THz time-domain spectroscopy or pump-probe techniques. Close https://www.sciencedirect.com/science/article/pii/S1386947724002248 doi:https://doi.org/10.1016/j.physe.2024.116120 Close
42.	Aleksey Girich, Liubov Ivzhenko, Ganna Kharchenko, Sergey Polevoy, Sergey Tarapov, Maciej Krawczyk, Jarosław W. Kłos Existence of edge modes in periodic microstrip transmission line Scientific Reports, 14 (1), pp. 16477, 2024, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{girich_existence_2024, title = {Existence of edge modes in periodic microstrip transmission line}, author = {Aleksey Girich and Liubov Ivzhenko and Ganna Kharchenko and Sergey Polevoy and Sergey Tarapov and Maciej Krawczyk and Jarosław W. Kłos}, url = {https://www.nature.com/articles/s41598-024-67610-9}, doi = {10.1038/s41598-024-67610-9}, issn = {2045-2322}, year = {2024}, date = {2024-07-16}, urldate = {2024-07-17}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {16477}, abstract = {The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of the symmetric unit cell can be distinguished by 0 or pi Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity and characterised by a significant group delay.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The microstrip of modulated width is a realization of a one-dimensional photonic crystal operating in the microwave regime. Like any photonic crystal, the periodic microstrip is characterised by the presence of frequency bands and band gaps that enable and prohibit wave propagation, respectively. The frequency bands for microstrip of the symmetric unit cell can be distinguished by 0 or pi Zak phase. The sum of these topological parameters for all bands below a given frequency gap determines the value of the surface impedance at the end of the microstrip. We demonstrate that edge modes are absent in a finite microstrip terminated at both ends in the centres of unit cells, but they can be induced by adding the defected cells. Edge modes present at both ends of the microstrip enable microwave tunneling with high transitivity in the frequency gap with or without a change in phase. This has been demonstrated experimentally and developed in detail using numerical simulations and model calculations. The investigated system, with a doublet of edge modes in the frequency gap, can be considered as a narrow passband filter of high selectivity and characterised by a significant group delay. Close https://www.nature.com/articles/s41598-024-67610-9 doi:10.1038/s41598-024-67610-9 Close
41.	Mathieu Moalic, Mateusz Zelent, Krzysztof Szulc, Maciej Krawczyk The role of non-uniform magnetization texture for magnon–magnon coupling in an antidot lattice Scientific Reports, 14 (1), pp. 11501, 2024, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{moalic_role_2024, title = {The role of non-uniform magnetization texture for magnon–magnon coupling in an antidot lattice}, author = {Mathieu Moalic and Mateusz Zelent and Krzysztof Szulc and Maciej Krawczyk}, url = {https://www.nature.com/articles/s41598-024-61246-5}, doi = {10.1038/s41598-024-61246-5}, issn = {2045-2322}, year = {2024}, date = {2024-05-20}, urldate = {2024-05-23}, journal = {Scientific Reports}, volume = {14}, number = {1}, pages = {11501}, abstract = {We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon–magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk–rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon–magnon coupling, highlighting the significant role of exchange interactions in the hybridization.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We numerically study the spin-wave dynamics in an antidot lattice based on a Co/Pd multilayer structure with reduced perpendicular magnetic anisotropy at the edges of the antidots. This structure forms a magnonic crystal with a periodic antidot pattern and a periodic magnetization configuration consisting of out-of-plane magnetized bulk and in-plane magnetized rims. Our results show a different behavior of spin waves in the bulk and in the rims under varying out-of-plane external magnetic field strength, revealing complex spin-wave spectra and hybridizations between the modes of these two subsystems. A particularly strong magnon–magnon coupling, due to exchange interactions, is found between the fundamental bulk spin-wave mode and the second-order radial rim modes. However, the dynamical coupling between the spin-wave modes at low frequencies, involving the first-order radial rim modes, is masked by the changes in the static magnetization at the bulk–rim interface with magnetic field changes. The study expands the horizons of magnonic-crystal research by combining periodic structural patterning and non-collinear magnetization texture to achieve strong magnon–magnon coupling, highlighting the significant role of exchange interactions in the hybridization. Close https://www.nature.com/articles/s41598-024-61246-5 doi:10.1038/s41598-024-61246-5 Close
40.	Uladzislau Makartsou, Mateusz Gołębiewski, Urszula Guzowska, Alexander Stognij, Ryszard Gieniusz, Maciej Krawczyk Spin-wave self-imaging: Experimental and numerical demonstration of caustic and Talbot-like diffraction patterns Applied Physics Letters, 124 (19), pp. 192406, 2024, ISSN: 0003-6951. Abstract \| Links \| BibTeX @article{10.1063/5.0195099, title = {Spin-wave self-imaging: Experimental and numerical demonstration of caustic and Talbot-like diffraction patterns}, author = {Uladzislau Makartsou and Mateusz Gołębiewski and Urszula Guzowska and Alexander Stognij and Ryszard Gieniusz and Maciej Krawczyk}, url = {https://doi.org/10.1063/5.0195099}, doi = {10.1063/5.0195099}, issn = {0003-6951}, year = {2024}, date = {2024-05-09}, journal = {Applied Physics Letters}, volume = {124}, number = {19}, pages = {192406}, abstract = {Extending the scope of the self-imaging phenomenon, traditionally associated with linear optics, to the domain of magnonics, this study presents the experimental demonstration and numerical analysis of spin-wave (SW) self-imaging in an in-plane magnetized yttrium iron garnet film. We explore this phenomenon using a setup in which a plane SW passes through a diffraction grating, and the resulting interference pattern is detected using Brillouin light scattering. We have varied the frequencies of the source dynamic magnetic field to discern the influence of the anisotropic dispersion relation and the caustic effect on the analyzed phenomenon. We found that at low frequencies and diffraction fields, the caustics determine the interference pattern. However, at large distances from the grating, when the waves of high diffraction order and number of slits contribute to the interference pattern, the self-imaging phenomenon and Talbot-like patterns are formed. This methodological approach not only sheds light on the behavior of SW interference under different conditions but also enhances our understanding of the SW self-imaging process in both isotropic and anisotropic media.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Extending the scope of the self-imaging phenomenon, traditionally associated with linear optics, to the domain of magnonics, this study presents the experimental demonstration and numerical analysis of spin-wave (SW) self-imaging in an in-plane magnetized yttrium iron garnet film. We explore this phenomenon using a setup in which a plane SW passes through a diffraction grating, and the resulting interference pattern is detected using Brillouin light scattering. We have varied the frequencies of the source dynamic magnetic field to discern the influence of the anisotropic dispersion relation and the caustic effect on the analyzed phenomenon. We found that at low frequencies and diffraction fields, the caustics determine the interference pattern. However, at large distances from the grating, when the waves of high diffraction order and number of slits contribute to the interference pattern, the self-imaging phenomenon and Talbot-like patterns are formed. This methodological approach not only sheds light on the behavior of SW interference under different conditions but also enhances our understanding of the SW self-imaging process in both isotropic and anisotropic media. Close https://doi.org/10.1063/5.0195099 doi:10.1063/5.0195099 Close
39.	Mateusz Gołębiewski, Riccardo Hertel, Massimiliano dÁquino, Vitaliy Vasyuchka, Mathias Weiler, Philipp Pirro, Maciej Krawczyk, Shunsuke Fukami, Hideo Ohno, Justin Llandro Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures ACS Applied Materials & Interfaces, 2024, ISSN: 1944-8244. Links \| BibTeX @article{Gołębiewski2024, title = {Collective Spin-Wave Dynamics in Gyroid Ferromagnetic Nanostructures}, author = {Mateusz Gołębiewski and Riccardo Hertel and Massimiliano dÁquino and Vitaliy Vasyuchka and Mathias Weiler and Philipp Pirro and Maciej Krawczyk and Shunsuke Fukami and Hideo Ohno and Justin Llandro}, url = {https://doi.org/10.1021/acsami.4c02366}, doi = {10.1021/acsami.4c02366}, issn = {1944-8244}, year = {2024}, date = {2024-04-22}, journal = {ACS Applied Materials & Interfaces}, publisher = {American Chemical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://doi.org/10.1021/acsami.4c02366 doi:10.1021/acsami.4c02366 Close
38.	Nikhil Kumar, Paweł Gruszecki, Mateusz Gołębiewski, Jarosław W. Kłos, Maciej Krawczyk Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode Advanced Quantum Technologies, n/a (n/a), pp. 2400015, 2024. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/qute.202400015, title = {Exciting High-Frequency Short-Wavelength Spin Waves using High Harmonics of a Magnonic Cavity Mode}, author = {Nikhil 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}, journal = {Advanced Quantum Technologies}, volume = {n/a}, number = {n/a}, 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} } Close 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. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/qute.202400015 doi:https://doi.org/10.1002/qute.202400015 Close
37.	Krzysztof Szulc, Yulia Kharlan, Pavlo Bondarenko, Elena V. Tartakovskaya, Maciej Krawczyk Impact of surface anisotropy on the spin-wave dynamics in a thin ferromagnetic film Phys. Rev. B, 109 , pp. 054430, 2024. Links \| BibTeX @article{PhysRevB.109.054430, title = {Impact of surface anisotropy on the spin-wave dynamics in a thin ferromagnetic film}, author = {Krzysztof Szulc and Yulia Kharlan and Pavlo Bondarenko and Elena V. Tartakovskaya and Maciej Krawczyk}, url = {https://link.aps.org/doi/10.1103/PhysRevB.109.054430}, doi = {10.1103/PhysRevB.109.054430}, year = {2024}, date = {2024-02-01}, journal = {Phys. Rev. B}, volume = {109}, pages = {054430}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevB.109.054430 doi:10.1103/PhysRevB.109.054430 Close
2023
36.	Sreedevi Janardhanan, Sławomir Mielcarek, Hubert Głowiński, Mateusz Kowacz, Piotr Kuświk, Maciej Krawczyk, Aleksandra Trzaskowska Investigation of spin wave dynamics in Au/CoFeB/Au multilayers with perpendicular magnetic anisotropy Scientific Reports, 13 (1), pp. 22494, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{Janardhanan2023b, title = {Investigation of spin wave dynamics in Au/CoFeB/Au multilayers with perpendicular magnetic anisotropy}, author = {Sreedevi Janardhanan and Sławomir Mielcarek and Hubert G{ł}owi{ń}ski and Mateusz Kowacz and Piotr Ku{ś}wik and Maciej Krawczyk and Aleksandra Trzaskowska}, url = {https://doi.org/10.1038/s41598-023-49859-8}, doi = {10.1038/s41598-023-49859-8}, issn = {2045-2322}, year = {2023}, date = {2023-12-15}, journal = {Scientific Reports}, volume = {13}, number = {1}, 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} } Close 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. Close https://doi.org/10.1038/s41598-023-49859-8 doi:10.1038/s41598-023-49859-8 Close
35.	Xue Liang, Jin Lan, Guoping Zhao, Mateusz Zelent, Maciej Krawczyk, Yan Zhou Bidirectional magnon-driven bimeron motion in ferromagnets Phys. Rev. B, 108 , pp. 184407, 2023. Links \| BibTeX @article{PhysRevB.108.184407, title = {Bidirectional magnon-driven bimeron motion in ferromagnets}, author = {Xue Liang and Jin Lan and Guoping Zhao and Mateusz Zelent and Maciej Krawczyk and Yan Zhou}, url = {https://link.aps.org/doi/10.1103/PhysRevB.108.184407}, doi = {10.1103/PhysRevB.108.184407}, year = {2023}, date = {2023-11-01}, journal = {Phys. Rev. B}, volume = {108}, pages = {184407}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevB.108.184407 doi:10.1103/PhysRevB.108.184407 Close
34.	A K Dhiman, R Gieniusz, J Kisielewski, P Mazalski, M Matczak, F Stobiecki, Paweł Gruszecki, Maciej Krawczyk, A Lynnyk, A Maziewski Hysteresis of magnetization statics and dynamics in [Pt/Co] multilayer Journal of Magnetism and Magnetic Materials, 587 , pp. 171338, 2023, ISSN: 0304-8853. Abstract \| Links \| BibTeX @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}, issn = {0304-8853}, year = {2023}, date = {2023-10-15}, journal = {Journal of Magnetism and Magnetic Materials}, volume = {587}, pages = {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} } Close 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. Close https://www.sciencedirect.com/science/article/pii/S0304885323009885 doi:https://doi.org/10.1016/j.jmmm.2023.171338 Close
33.	Sreedevi Janardhanan, Sławomir Mielcarek, Piotr Kuświk, Maciej Krawczyk, Aleksandra Trzaskowska High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer Journal of Magnetism and Magnetic Materials, 586 , pp. 171209, 2023, ISSN: 0304-8853. Abstract \| Links \| BibTeX @article{JANARDHANAN2023171209, title = {High-resolution Brillouin light scattering study on Ti/Au/Co/Ni multilayer}, author = {Sreedevi Janardhanan and Sławomir Mielcarek and Piotr 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}, issn = {0304-8853}, year = {2023}, date = {2023-09-01}, 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} } Close 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. Close https://www.sciencedirect.com/science/article/pii/S0304885323008594 doi:https://doi.org/10.1016/j.jmmm.2023.171209 Close
32.	Mateusz Zelent, Mathieu Moalic, Michal Mruczkiewicz, Xiaoguang Li, Yan Zhou, Maciej Krawczyk Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures Scientific Reports, 13 (1), pp. 13572, 2023, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{zelent_stabilization_2023, title = {Stabilization and racetrack application of asymmetric Néel skyrmions in hybrid nanostructures}, author = {Mateusz Zelent and Mathieu Moalic and Michal Mruczkiewicz and Xiaoguang Li and Yan Zhou and Maciej Krawczyk}, url = {https://www.nature.com/articles/s41598-023-40236-z}, doi = {10.1038/s41598-023-40236-z}, issn = {2045-2322}, year = {2023}, date = {2023-08-21}, urldate = {2023-08-24}, journal = {Scientific Reports}, volume = {13}, number = {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} } Close 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. Close https://www.nature.com/articles/s41598-023-40236-z doi:10.1038/s41598-023-40236-z Close
31.	Krzysztof Sobucki, Wojciech Śmigaj, Piotr Graczyk, Maciej Krawczyk, Paweł Gruszecki Magnon-Optic Effects with Spin-Wave Leaky Modes: Tunable Goos-Hänchen Shift and Wood’s Anomaly Nano Letters, 23 (15), pp. 6979-6984, 2023, (PMID: 37523860). Abstract \| Links \| BibTeX @article{doi:10.1021/acs.nanolett.3c01592, 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}, journal = {Nano Letters}, volume = {23}, number = {15}, pages = {6979-6984}, 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.}, note = {PMID: 37523860}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close 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. Close https://doi.org/10.1021/acs.nanolett.3c01592 doi:10.1021/acs.nanolett.3c01592 Close
30.	Uladzislau Makartsou, Mathieu Moalic, Mateusz Zelent, Michal Mruczkiewicz, Maciej Krawczyk Control of vortex chirality in a symmetric ferromagnetic ring using a ferromagnetic nanoelement Nanoscale, pp. -, 2023. Abstract \| Links \| BibTeX @article{D3NR00582H, title = {Control of vortex chirality in a symmetric ferromagnetic ring using a ferromagnetic nanoelement}, author = {Uladzislau Makartsou and Mathieu Moalic and Mateusz Zelent and Michal Mruczkiewicz and Maciej Krawczyk}, url = {http://dx.doi.org/10.1039/D3NR00582H}, doi = {10.1039/D3NR00582H}, year = {2023}, date = {2023-07-27}, journal = {Nanoscale}, pages = {-}, publisher = {The Royal Society of Chemistry}, abstract = {Controlling the vortex chirality in ferromagnetic nanodots and nanorings has been a topic of investigation for the last few years. Many control methods have been proposed and it has been found that the control is related to the breaking of the circular symmetry of the ring. In this paper, we present a theoretical study demonstrating the control of chirality in a symmetrical ferromagnetic nanoring by breaking the circular symmetry of the system by placing an elongated ferromagnetic nanoelement inside the ring. Here, the stray magnetostatic field exerted by the asymmetrically placed nanoelement determines the movement of the domain walls upon re-magnetization of the nanoring and the resulting chirality in remanence. Thus, the use of a nanoelement not only allows control of the chirality of the vortex state in an isolated ring, but also offers an opportunity to control magnetization in denser nanoring systems, as well as for spintronic and magnonic applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Controlling the vortex chirality in ferromagnetic nanodots and nanorings has been a topic of investigation for the last few years. Many control methods have been proposed and it has been found that the control is related to the breaking of the circular symmetry of the ring. In this paper, we present a theoretical study demonstrating the control of chirality in a symmetrical ferromagnetic nanoring by breaking the circular symmetry of the system by placing an elongated ferromagnetic nanoelement inside the ring. Here, the stray magnetostatic field exerted by the asymmetrically placed nanoelement determines the movement of the domain walls upon re-magnetization of the nanoring and the resulting chirality in remanence. Thus, the use of a nanoelement not only allows control of the chirality of the vortex state in an isolated ring, but also offers an opportunity to control magnetization in denser nanoring systems, as well as for spintronic and magnonic applications. Close http://dx.doi.org/10.1039/D3NR00582H doi:10.1039/D3NR00582H Close
29.	Wojciech Śmigaj, Krzysztof Sobucki, Paweł Gruszecki, Maciej Krawczyk Modal approach to modeling spin wave scattering Phys. Rev. B, 108 , pp. 014418, 2023. Abstract \| Links \| BibTeX @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 = {2023-07-01}, journal = {Phys. Rev. B}, volume = {108}, pages = {014418}, publisher = {American Physical Society}, 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} } Close 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. Close https://link.aps.org/doi/10.1103/PhysRevB.108.014418 doi:10.1103/PhysRevB.108.014418 Close
28.	Mateusz Gołębiewski, Hanna Reshetniak, Uladzislau Makartsou, Maciej Krawczyk, Arjen van den Berg, Sam Ladak, Anjan Barman Spin-Wave Spectral Analysis in Crescent-Shaped Ferromagnetic Nanorods Phys. Rev. Appl., 19 , pp. 064045, 2023. Abstract \| Links \| BibTeX @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 Arjen van den Berg and Sam Ladak and Anjan 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}, pages = {064045}, publisher = {American Physical Society}, 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} } Close 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). Close https://link.aps.org/doi/10.1103/PhysRevApplied.19.064045 doi:10.1103/PhysRevApplied.19.064045 Close
27.	Dariia Popadiuk, Elena V. Tartakovskaya, Maciej Krawczyk, Kostyantyn Guslienko Emergent Magnetic Field and Nonzero Gyrovector of the Toroidal Magnetic Hopfion physica status solidi (RRL) – Rapid Research Letters, n/a (n/a), pp. 2300131, 2023. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/pssr.202300131, title = {Emergent Magnetic Field and Nonzero Gyrovector of the Toroidal Magnetic Hopfion}, author = {Dariia Popadiuk and Elena V. Tartakovskaya and Maciej Krawczyk and Kostyantyn Guslienko}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/pssr.202300131}, doi = {https://doi.org/10.1002/pssr.202300131}, year = {2023}, date = {2023-05-13}, journal = {physica status solidi (RRL) – Rapid Research Letters}, volume = {n/a}, number = {n/a}, pages = {2300131}, 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 \| QH \|=1$łeft\|right. Q_textĦ łeft\|right. = 1$ 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} } Close 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 \| QH \|=1$łeft\|right. Q_textĦ łeft\|right. = 1$ 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. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/pssr.202300131 doi:https://doi.org/10.1002/pssr.202300131 Close
26.	R Mehta, Mathieu Moalic, Maciej Krawczyk, S Saha Tunability of spin-wave spectra in a 2D triangular shaped magnonic fractals Journal of Physics: Condensed Matter, 35 (32), pp. 324002, 2023. Abstract \| Links \| BibTeX @article{Mehta_2023, 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}, url = {https://dx.doi.org/10.1088/1361-648X/acd15f}, doi = {10.1088/1361-648X/acd15f}, year = {2023}, date = {2023-05-12}, journal = {Journal of Physics: Condensed Matter}, volume = {35}, number = {32}, pages = {324002}, publisher = {IOP Publishing}, 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} } Close 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. Close https://dx.doi.org/10.1088/1361-648X/acd15f Close
25.	Jan Kisielewski, Paweł Gruszecki, Maciej Krawczyk, Vitalii Zablotskii, Andrzej Maziewski Between waves and patterns: Spin wave freezing in films with Dzyaloshinskii-Moriya interaction Phys. Rev. B, 107 , pp. 134416, 2023. Abstract \| Links \| BibTeX @article{PhysRevB.107.134416, title = {Between waves and patterns: Spin wave freezing in films with Dzyaloshinskii-Moriya interaction}, author = {Jan Kisielewski and Paweł Gruszecki and Maciej Krawczyk and Vitalii Zablotskii and Andrzej Maziewski}, url = {https://link.aps.org/doi/10.1103/PhysRevB.107.134416}, doi = {10.1103/PhysRevB.107.134416}, year = {2023}, date = {2023-04-12}, journal = {Phys. Rev. B}, volume = {107}, pages = {134416}, publisher = {American Physical Society}, 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} } Close 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. Close https://link.aps.org/doi/10.1103/PhysRevB.107.134416 doi:10.1103/PhysRevB.107.134416 Close
24.	Oleksandr Pastukh, Malgorzata Kac, Svitlana Pastukh, Dominika Kuźma, Mateusz Zelent, Maciej Krawczyk, Łukasz Laskowski Magnetic Behavior of the Arrays of Iron Cylindrical Nanostructures: Atomistic Spin Model Simulations Crystals, 13 (3), 2023, ISSN: 2073-4352. Abstract \| Links \| BibTeX @article{cryst13030537, title = {Magnetic Behavior of the Arrays of Iron Cylindrical Nanostructures: Atomistic Spin Model Simulations}, author = {Oleksandr Pastukh and Malgorzata Kac and Svitlana Pastukh and Dominika Kuźma and Mateusz Zelent and Maciej Krawczyk and Łukasz Laskowski}, url = {https://www.mdpi.com/2073-4352/13/3/537}, doi = {10.3390/cryst13030537}, issn = {2073-4352}, year = {2023}, date = {2023-03-21}, journal = {Crystals}, volume = {13}, number = {3}, abstract = {Cylindrical ferromagnetic nanowires are of particular interest in nanomaterials science due to various manufacturing methods and a wide range of applications in nanotechnology, with special attention given to those with diameters less than the single domain limit. In the current study, the simulations of magnetic properties of isolated iron nanowires with a diameter of 5 nm and various aspect ratios, as well as two types of arrays of such nanowires (with hexagonal and square arrangement), were performed using atomistic spin model. In the case of a single nanowire, change of coercive field for different applied field directions with aspect ratio was discussed. It was shown that the evolution of the magnetization reversal mechanism from coherent rotation to domain wall propagation appears with increasing length of single nanowire. For the arrays of cylindrical nanostructures, it was revealed that different number of nearest neighbors for each nanostructure in square and hexagonal arrays have an influence on their magnetostatic interactions, which are the most significant for shortest interwire distances. The corresponding spin configurations during the remagnetization process showed the appearance of intermediate magnetization states (when a part of wires is magnetized parallel and part antiparallel to the field direction), connected with Barkhausen effect, which influence the observed hysteresis curves.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Cylindrical ferromagnetic nanowires are of particular interest in nanomaterials science due to various manufacturing methods and a wide range of applications in nanotechnology, with special attention given to those with diameters less than the single domain limit. In the current study, the simulations of magnetic properties of isolated iron nanowires with a diameter of 5 nm and various aspect ratios, as well as two types of arrays of such nanowires (with hexagonal and square arrangement), were performed using atomistic spin model. In the case of a single nanowire, change of coercive field for different applied field directions with aspect ratio was discussed. It was shown that the evolution of the magnetization reversal mechanism from coherent rotation to domain wall propagation appears with increasing length of single nanowire. For the arrays of cylindrical nanostructures, it was revealed that different number of nearest neighbors for each nanostructure in square and hexagonal arrays have an influence on their magnetostatic interactions, which are the most significant for shortest interwire distances. The corresponding spin configurations during the remagnetization process showed the appearance of intermediate magnetization states (when a part of wires is magnetized parallel and part antiparallel to the field direction), connected with Barkhausen effect, which influence the observed hysteresis curves. Close https://www.mdpi.com/2073-4352/13/3/537 doi:10.3390/cryst13030537 Close
2022
23.	Mathieu Moalic, Maciej Krawczyk, Mateusz Zelent Spin-wave spectra in antidot lattice with inhomogeneous perpendicular magnetic anisotropy Journal of Applied Physics, 132 (21), pp. 213901, 2022. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0128621, title = {Spin-wave spectra in antidot lattice with inhomogeneous perpendicular magnetic anisotropy}, author = {Mathieu Moalic and Maciej Krawczyk and Mateusz Zelent}, url = {https://doi.org/10.1063/5.0128621}, doi = {10.1063/5.0128621}, year = {2022}, date = {2022-12-01}, journal = {Journal of Applied Physics}, volume = {132}, number = {21}, 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} } Close 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. Close https://doi.org/10.1063/5.0128621 doi:10.1063/5.0128621 Close
22.	Mateusz Zelent, Paweł Gruszecki, Mathieu Moalic, Olav Hellwig, Anjan Barman, Maciej Krawczyk Spin dynamics in patterned magnetic multilayers with perpendicular magnetic anisotropy Macedo, Rair (Ed.): 73 , pp. 1-51, Academic Press, 2022, ISSN: 0081-1947. Abstract \| Links \| BibTeX @incollection{ZELENT20221, title = {Spin dynamics in patterned magnetic multilayers with perpendicular magnetic anisotropy}, author = {Mateusz Zelent and Paweł Gruszecki and Mathieu Moalic and Olav Hellwig and Anjan Barman and Maciej Krawczyk}, editor = {Rair Macedo}, url = {https://www.sciencedirect.com/science/article/pii/S0081194722000029}, doi = {https://doi.org/10.1016/bs.ssp.2022.08.002}, issn = {0081-1947}, year = {2022}, date = {2022-10-27}, volume = {73}, pages = {1-51}, publisher = {Academic Press}, series = {Solid State Physics}, abstract = {The magnetization dynamics in nanostructures has been extensively studied in the last decades, and nanomagnetism has evolved significantly over that time, discovering new effects, developing numerous applications, and identifying promising new directions. This includes magnonics, an emerging research field oriented on the study of spin-wave dynamics and their applications. In this context, thin ferromagnetic films with perpendicular magnetic anisotropy (PMA) offer interesting opportunities to study spin waves, in particular, due to out-of-plane magnetization in remanence or at relatively weak external magnetic fields. This is the only magnetization configuration offering isotropic in-plane spin-wave propagation within the sample plane, the forward volume magnetostatic spin-wave geometry. The isotropic dispersion relation is highly important in designing signal-processing devices, offering superior prospects for direct replicating various concepts from photonics into magnonics. Analogous to photonic or phononic crystals, which are the building blocks of optoelectronics and phononics, magnonic crystals are considered as key components in magnonics applications. Arrays of nanodots and structured ferromagnetic thin films with a periodic array of holes, popularly known as antidot lattices based on PMA multilayers, have been recently studied. Novel magnonic properties related to propagating spin-wave modes, exploitation of the band gaps, and confined modes were demonstrated. Also, the existence of nontrivial magnonic band topologies has been shown. Moreover, the combination of PMA and Dzyaloshinskii–Moriya interaction leads to the formation of chiral magnetization states, including Néel domain walls, skyrmions, and skyrmionium states. This promotes the multilayers with PMA as an interesting topic for magnonics and this chapter reviews the background and attempts to provide future perspectives in this research field.}, keywords = {}, pubstate = {published}, tppubtype = {incollection} } Close The magnetization dynamics in nanostructures has been extensively studied in the last decades, and nanomagnetism has evolved significantly over that time, discovering new effects, developing numerous applications, and identifying promising new directions. This includes magnonics, an emerging research field oriented on the study of spin-wave dynamics and their applications. In this context, thin ferromagnetic films with perpendicular magnetic anisotropy (PMA) offer interesting opportunities to study spin waves, in particular, due to out-of-plane magnetization in remanence or at relatively weak external magnetic fields. This is the only magnetization configuration offering isotropic in-plane spin-wave propagation within the sample plane, the forward volume magnetostatic spin-wave geometry. The isotropic dispersion relation is highly important in designing signal-processing devices, offering superior prospects for direct replicating various concepts from photonics into magnonics. Analogous to photonic or phononic crystals, which are the building blocks of optoelectronics and phononics, magnonic crystals are considered as key components in magnonics applications. Arrays of nanodots and structured ferromagnetic thin films with a periodic array of holes, popularly known as antidot lattices based on PMA multilayers, have been recently studied. Novel magnonic properties related to propagating spin-wave modes, exploitation of the band gaps, and confined modes were demonstrated. Also, the existence of nontrivial magnonic band topologies has been shown. Moreover, the combination of PMA and Dzyaloshinskii–Moriya interaction leads to the formation of chiral magnetization states, including Néel domain walls, skyrmions, and skyrmionium states. This promotes the multilayers with PMA as an interesting topic for magnonics and this chapter reviews the background and attempts to provide future perspectives in this research field. Close https://www.sciencedirect.com/science/article/pii/S0081194722000029 doi:https://doi.org/10.1016/bs.ssp.2022.08.002 Close
21.	Krzysztof Sobucki, Maciej Krawczyk, Elena V. Tartakovskaya, Piotr Graczyk Magnon spectrum of Bloch hopfion beyond ferromagnetic resonance APL Materials, 10 (9), pp. 091103, 2022. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0100484, title = {Magnon spectrum of Bloch hopfion beyond ferromagnetic resonance}, author = {Krzysztof Sobucki and Maciej Krawczyk and Elena V. Tartakovskaya and Piotr Graczyk}, url = {https://doi.org/10.1063/5.0100484}, doi = {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} } Close 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. Close https://doi.org/10.1063/5.0100484 doi:10.1063/5.0100484 Close
20.	Katarzyna Kotus, Mathieu Moalic, Mateusz Zelent, Maciej Krawczyk, Paweł Gruszecki Scattering of spin waves in a multimode waveguide under the influence of confined magnetic skyrmion APL Materials, 10 (9), pp. 091101, 2022. Abstract \| Links \| BibTeX @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} } Close 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. Close https://doi.org/10.1063/5.0100594 doi:10.1063/5.0100594 Close
19.	Krzysztof Szulc, Silvia Tacchi, Aurelio Hierro-Rodríguez, Javier Díaz, Paweł Gruszecki, Piotr Graczyk, Carlos Quirós, Daniel Markó, José Ignacio Martín, María Vélez, David S Schmool, Giovanni Carlotti, Maciej Krawczyk, Luis Manuel Álvarez-Prado Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers ACS Nano, 0 (0), pp. 0, 2022, (PMID: 36043881). Abstract \| Links \| BibTeX @article{doi:10.1021/acsnano.2c04256, title = {Reconfigurable Magnonic Crystals Based on Imprinted Magnetization Textures in Hard and Soft Dipolar-Coupled Bilayers}, author = {Krzysztof Szulc and Silvia Tacchi and Aurelio Hierro-Rodríguez and Javier Díaz and Paweł Gruszecki and Piotr Graczyk and Carlos Quirós and Daniel Markó and José Ignacio Martín and María Vélez and David S Schmool and Giovanni Carlotti and Maciej Krawczyk and Luis Manuel Álvarez-Prado}, url = {https://doi.org/10.1021/acsnano.2c04256}, doi = {10.1021/acsnano.2c04256}, year = {2022}, date = {2022-08-31}, journal = {ACS Nano}, volume = {0}, number = {0}, pages = {0}, 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.}, note = {PMID: 36043881}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close 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. Close https://doi.org/10.1021/acsnano.2c04256 doi:10.1021/acsnano.2c04256 Close
18.	Szymon Mieszczak, Maciej Krawczyk, Jarosław W. Kłos Spin-wave localization on phasonic defects in a one-dimensional magnonic quasicrystal Phys. Rev. B, 106 , pp. 064430, 2022. Abstract \| Links \| BibTeX @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}, pages = {064430}, publisher = {American Physical Society}, 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} } Close 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. Close https://link.aps.org/doi/10.1103/PhysRevB.106.064430 doi:10.1103/PhysRevB.106.064430 Close
17.	Mateusz Gołȩbiewski, Paweł Gruszecki, Maciej Krawczyk Self-Imaging of Spin Waves in Thin, Multimode Ferromagnetic Waveguides IEEE Transactions on Magnetics, 58 (8), pp. 1-5, 2022, ISSN: 1941-0069. Abstract \| Links \| BibTeX @article{9668947, title = {Self-Imaging of Spin Waves in Thin, Multimode Ferromagnetic Waveguides}, author = {Mateusz Gołȩbiewski and Paweł Gruszecki and Maciej Krawczyk}, doi = {10.1109/TMAG.2022.3140280}, issn = {1941-0069}, year = {2022}, date = {2022-08-01}, journal = {IEEE Transactions on Magnetics}, volume = {58}, number = {8}, pages = {1-5}, abstract = {Self-imaging of waves is an intriguing and spectacular effect. The phenomenon was first observed for light in 1836 by Henry Fox Talbot and to this day is the subject of research in many areas of physics, for various types of waves and in terms of different applications. This article is a Talbot-effect study for spin waves (SWs) in systems composed of a thin, ferromagnetic waveguide with a series of single-mode sources of SWs flowing into it. The proposed systems are studied with the use of micromagnetic simulations, and the SW self-imaging dependencies on many parameters are examined. We formulated conditions required for the formation of self-images and suitable for experimental realization. The results of the research form the basis for the further development of self-imaging-based magnonic devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Self-imaging of waves is an intriguing and spectacular effect. The phenomenon was first observed for light in 1836 by Henry Fox Talbot and to this day is the subject of research in many areas of physics, for various types of waves and in terms of different applications. This article is a Talbot-effect study for spin waves (SWs) in systems composed of a thin, ferromagnetic waveguide with a series of single-mode sources of SWs flowing into it. The proposed systems are studied with the use of micromagnetic simulations, and the SW self-imaging dependencies on many parameters are examined. We formulated conditions required for the formation of self-images and suitable for experimental realization. The results of the research form the basis for the further development of self-imaging-based magnonic devices. Close doi:10.1109/TMAG.2022.3140280 Close
16.	Mateusz Gołębiewski, Paweł Gruszecki, Maciej Krawczyk Self-Imaging Based Programmable Spin-Wave Lookup Tables Advanced Electronic Materials, n/a (n/a), pp. 2200373, 2022. Abstract \| Links \| BibTeX @article{https://doi.org/10.1002/aelm.202200373, title = {Self-Imaging Based Programmable Spin-Wave Lookup Tables}, author = {Mateusz Gołębiewski and Paweł Gruszecki and Maciej Krawczyk}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202200373}, doi = {https://doi.org/10.1002/aelm.202200373}, year = {2022}, date = {2022-07-21}, journal = {Advanced Electronic Materials}, volume = {n/a}, number = {n/a}, pages = {2200373}, abstract = {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} } Close 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. Close https://onlinelibrary.wiley.com/doi/abs/10.1002/aelm.202200373 doi:https://doi.org/10.1002/aelm.202200373 Close
15.	Jingyuan Zhou, Mateusz Zelent, Zhaochu Luo, Valerio Scagnoli, Maciej Krawczyk, Laura J Heyderman, Susmita Saha Precessional dynamics of geometrically scaled magnetostatic spin waves in two-dimensional magnonic fractals Phys. Rev. B, 105 , pp. 174415, 2022. Abstract \| Links \| BibTeX @article{PhysRevB.105.174415, title = {Precessional dynamics of geometrically scaled magnetostatic spin waves in two-dimensional magnonic fractals}, author = {Jingyuan Zhou and Mateusz Zelent and Zhaochu Luo and Valerio Scagnoli and Maciej Krawczyk and Laura J Heyderman and Susmita Saha}, url = {https://link.aps.org/doi/10.1103/PhysRevB.105.174415}, doi = {10.1103/PhysRevB.105.174415}, year = {2022}, date = {2022-05-13}, journal = {Phys. Rev. B}, volume = {105}, pages = {174415}, publisher = {American Physical Society}, abstract = {The control of spin waves in periodic magnetic structures has facilitated the realization of many functional magnonic devices, such as band stop filters and magnonic transistors, where the geometry of the crystal structure plays an important role. Here, we report on the magnetostatic mode formation in an artificial magnetic structure, going beyond the crystal geometry to a fractal structure, where the mode formation is related to the geometric scaling of the fractal structure. Specifically, the precessional dynamics was measured in samples with structures going from simple geometric structures toward a Sierpinski carpet and a Sierpinski triangle. The experimentally observed evolution of the precessional motion could be linked to the progression in the geometric structures that results in a modification of the demagnetizing field. Furthermore, we have found sets of modes at the ferromagnetic resonance frequency that form a scaled spatial distribution following the geometric scaling. Based on this, we have determined the two conditions for such mode formation to occur. One condition is that the associated magnetic boundaries must scale accordingly, and the other condition is that the region where the mode occurs must not coincide with the regions for the edge modes. This established relationship between the fractal geometry and the mode formation in magnetic fractals provides guiding principles for their use in magnonics applications.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The control of spin waves in periodic magnetic structures has facilitated the realization of many functional magnonic devices, such as band stop filters and magnonic transistors, where the geometry of the crystal structure plays an important role. Here, we report on the magnetostatic mode formation in an artificial magnetic structure, going beyond the crystal geometry to a fractal structure, where the mode formation is related to the geometric scaling of the fractal structure. Specifically, the precessional dynamics was measured in samples with structures going from simple geometric structures toward a Sierpinski carpet and a Sierpinski triangle. The experimentally observed evolution of the precessional motion could be linked to the progression in the geometric structures that results in a modification of the demagnetizing field. Furthermore, we have found sets of modes at the ferromagnetic resonance frequency that form a scaled spatial distribution following the geometric scaling. Based on this, we have determined the two conditions for such mode formation to occur. One condition is that the associated magnetic boundaries must scale accordingly, and the other condition is that the region where the mode occurs must not coincide with the regions for the edge modes. This established relationship between the fractal geometry and the mode formation in magnetic fractals provides guiding principles for their use in magnonics applications. Close https://link.aps.org/doi/10.1103/PhysRevB.105.174415 doi:10.1103/PhysRevB.105.174415 Close
14.	Paweł Gruszecki, Konstantin Y Guslienko, Igor L Lyubchanskii, Maciej Krawczyk Inelastic Spin-Wave Beam Scattering by Edge-Localized Spin Waves in a Ferromagnetic Thin Film Phys. Rev. Applied, 17 , pp. 044038, 2022. Abstract \| Links \| BibTeX @article{PhysRevApplied.17.044038, title = {Inelastic Spin-Wave Beam Scattering by Edge-Localized Spin Waves in a Ferromagnetic Thin Film}, author = {Paweł Gruszecki and Konstantin Y Guslienko and Igor L Lyubchanskii and Maciej Krawczyk}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.17.044038}, doi = {10.1103/PhysRevApplied.17.044038}, year = {2022}, date = {2022-04-20}, journal = {Phys. Rev. Applied}, volume = {17}, pages = {044038}, publisher = {American Physical Society}, abstract = {Spin waves are promising chargeless information carriers for the future, energetically efficient beyond CMOS systems. Among many advantages are the ease of achieving nonlinearity, the variety of possible interactions, and excitation types. Although the rapidly developing magnonic research has already yielded impressive realizations, multimode nonlinear effects, particularly with propagating waves and their nanoscale realizations, are still an open research problem.We theoretically study the dynamic interactions of spin waves confined to the edge of a thin ferromagnetic film with the spin-wave beam incident at this edge. We find inelastically scattered spin-wave beams at frequencies increased and decreased by the frequency of the edge spin-wave relative to the specularly reflected beam. We observe a strong dependence of the angular shift of the inelastic scattered spin-wave beam on the edge-mode frequency, which allows us to propose a magnonic demultiplexing of the signal encoded in spin waves propagating along the edge. Since dynamic magnetostatic interactions, which are ubiquitous in the spin-wave dynamics, are decisive in this process, this indicates the possibility of implementing the presented effects in other configurations and their use in magnonic systems.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Spin waves are promising chargeless information carriers for the future, energetically efficient beyond CMOS systems. Among many advantages are the ease of achieving nonlinearity, the variety of possible interactions, and excitation types. Although the rapidly developing magnonic research has already yielded impressive realizations, multimode nonlinear effects, particularly with propagating waves and their nanoscale realizations, are still an open research problem.We theoretically study the dynamic interactions of spin waves confined to the edge of a thin ferromagnetic film with the spin-wave beam incident at this edge. We find inelastically scattered spin-wave beams at frequencies increased and decreased by the frequency of the edge spin-wave relative to the specularly reflected beam. We observe a strong dependence of the angular shift of the inelastic scattered spin-wave beam on the edge-mode frequency, which allows us to propose a magnonic demultiplexing of the signal encoded in spin waves propagating along the edge. Since dynamic magnetostatic interactions, which are ubiquitous in the spin-wave dynamics, are decisive in this process, this indicates the possibility of implementing the presented effects in other configurations and their use in magnonic systems. Close https://link.aps.org/doi/10.1103/PhysRevApplied.17.044038 doi:10.1103/PhysRevApplied.17.044038 Close
13.	Yuliya S Dadoenkova, Maciej Krawczyk, Igor L Lyubchanskii Goos-Hoenchen shift at Brillouin light scattering by a magnetostatic wave in the Damon-Eshbach configuration [Invited] Opt. Mater. Express, 12 (2), pp. 717–726, 2022. Abstract \| Links \| BibTeX @article{Dadoenkova:22, title = {Goos-Hoenchen shift at Brillouin light scattering by a magnetostatic wave in the Damon-Eshbach configuration [Invited]}, author = {Yuliya S Dadoenkova and Maciej Krawczyk and Igor L Lyubchanskii}, url = {http://opg.optica.org/ome/abstract.cfm?URI=ome-12-2-717}, doi = {10.1364/OME.447984}, year = {2022}, date = {2022-02-12}, journal = {Opt. Mater. Express}, volume = {12}, number = {2}, pages = {717--726}, publisher = {OSA}, abstract = {The lateral shift of an optical beam undergoing Brillouin light scattering by a spin wave propagating along the interface between magnetic and dielectric media (Damon-Eshbach configuration) in the total internal reflection geometry is studied theoretically. Linear and quadratic magneto-optic terms in polarization are taken into account. It is shown that the lateral shift depends on the polarization (s- or p-) state of the scattered electromagnetic wave as well as on the frequency of the spin wave.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The lateral shift of an optical beam undergoing Brillouin light scattering by a spin wave propagating along the interface between magnetic and dielectric media (Damon-Eshbach configuration) in the total internal reflection geometry is studied theoretically. Linear and quadratic magneto-optic terms in polarization are taken into account. It is shown that the lateral shift depends on the polarization (s- or p-) state of the scattered electromagnetic wave as well as on the frequency of the spin wave. Close http://opg.optica.org/ome/abstract.cfm?URI=ome-12-2-717 doi:10.1364/OME.447984 Close
12.	A V Chumak, P Kabos, M Wu, C Abert, C Adelmann, A O Adeyeye, J Akerman, F G Aliev, A Anane, A Awad, C H Back, A Barman, G E W Bauer, M Becherer, E N Beginin, V A S V Bittencourt, Y M Blanter, P Bortolotti, I Boventer, D A Bozhko, S A Bunyaev, J J Carmiggelt, R R Cheenikundil, F Ciubotaru, S Cotofana, G Csaba, O V Dobrovolskiy, C Dubs, M Elyasi, K G Fripp, H Fulara, I A Golovchanskiy, C Gonzalez-Ballestero, Piotr Graczyk, D Grundler, Paweł Gruszecki, G Gubbiotti, K Guslienko, A Haldar, S Hamdioui, R Hertel, B Hillebrands, T Hioki, A Houshang, C -M Hu, H Huebl, M Huth, E Iacocca, M B Jungfleisch, G N Kakazei, A Khitun, R Khymyn, T Kikkawa, M Kloui, O Klein, Jarosław W. Kłos, S Knauer, S Koraltan, M Kostylev, Maciej Krawczyk, I N Krivorotov, V V Kruglyak, D Lachance-Quirion, S Ladak, R Lebrun, Y Li, M Lindner, R Macedo, S Mayr, G A Melkov, Szymon Mieszczak, Y Nakamura, H T Nembach, A A Nikitin, S A Nikitov, V Novosad, J A Otalora, Y Otani, A Papp, B Pigeau, P Pirro, W Porod, F Porrati, H Qin, Bivas Rana, T Reimann, F Riente, O Romero-Isart, A Ross, A V Sadovnikov, A R Safin, E Saitoh, G Schmidt, H Schultheiss, K Schultheiss, A A Serga, S Sharma, J M Shaw, D Suess, O Surzhenko, Krzysztof Szulc, T Taniguchi, M Urbanek, K Usami, A B Ustinov, T van der Sar, S van Dijken, V I Vasyuchka, R Verba, Viola S Kusminskiy, Q Wang, M Weides, M Weiler, S Wintz, S P Wolski, X Zhang Advances in Magnetics Roadmap on Spin-Wave Computing IEEE Trans. Magn., 58 (6), pp. 1-72, 2022, ISSN: 1941-0069. Abstract \| Links \| BibTeX @article{9706176, title = {Advances in Magnetics Roadmap on Spin-Wave Computing}, author = {A V Chumak and P Kabos and M Wu and C Abert and C Adelmann and A O Adeyeye and J Akerman and F G Aliev and A Anane and A Awad and C H Back and A Barman and G E W Bauer and M Becherer and E N Beginin and V A S V Bittencourt and Y M Blanter and P Bortolotti and I Boventer and D A Bozhko and S A Bunyaev and J J Carmiggelt and R R Cheenikundil and F Ciubotaru and S Cotofana and G Csaba and O V Dobrovolskiy and C Dubs and M Elyasi and K G Fripp and H Fulara and I A Golovchanskiy and C Gonzalez-Ballestero and Piotr Graczyk and D Grundler and Paweł Gruszecki and G Gubbiotti and K Guslienko and A Haldar and S Hamdioui and R Hertel and B Hillebrands and T Hioki and A Houshang and C -M Hu and H Huebl and M Huth and E Iacocca and M B Jungfleisch and G N Kakazei and A Khitun and R Khymyn and T Kikkawa and M Kloui and O Klein and Jarosław W. Kłos and S Knauer and S Koraltan and M Kostylev and Maciej Krawczyk and I N Krivorotov and V V Kruglyak and D Lachance-Quirion and S Ladak and R Lebrun and Y Li and M Lindner and R Macedo and S Mayr and G A Melkov and Szymon Mieszczak and Y Nakamura and H T Nembach and A A Nikitin and S A Nikitov and V Novosad and J A Otalora and Y Otani and A Papp and B Pigeau and P Pirro and W Porod and F Porrati and H Qin and Bivas Rana and T Reimann and F Riente and O Romero-Isart and A Ross and A V Sadovnikov and A R Safin and E Saitoh and G Schmidt and H Schultheiss and K Schultheiss and A A Serga and S Sharma and J M Shaw and D Suess and O Surzhenko and Krzysztof Szulc and T Taniguchi and M Urbanek and K Usami and A B Ustinov and T van der Sar and S van Dijken and V I Vasyuchka and R Verba and Viola S Kusminskiy and Q Wang and M Weides and M Weiler and S Wintz and S P Wolski and X Zhang}, doi = {10.1109/TMAG.2022.3149664}, issn = {1941-0069}, year = {2022}, date = {2022-02-07}, journal = {IEEE Trans. Magn.}, volume = {58}, number = {6}, pages = {1-72}, abstract = {Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors, which covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with the Boolean digital data, unconventional approaches, such as neuromorphic computing, and the progress toward magnon-based quantum computing. This article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of current challenges and the outlook of further development for each research direction.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnonics addresses the physical properties of spin waves and utilizes them for data processing. Scalability down to atomic dimensions, operation in the GHz-to-THz frequency range, utilization of nonlinear and nonreciprocal phenomena, and compatibility with CMOS are just a few of many advantages offered by magnons. Although magnonics is still primarily positioned in the academic domain, the scientific and technological challenges of the field are being extensively investigated, and many proof-of-concept prototypes have already been realized in laboratories. This roadmap is a product of the collective work of many authors, which covers versatile spin-wave computing approaches, conceptual building blocks, and underlying physical phenomena. In particular, the roadmap discusses the computation operations with the Boolean digital data, unconventional approaches, such as neuromorphic computing, and the progress toward magnon-based quantum computing. This article is organized as a collection of sub-sections grouped into seven large thematic sections. Each sub-section is prepared by one or a group of authors and concludes with a brief description of current challenges and the outlook of further development for each research direction. Close doi:10.1109/TMAG.2022.3149664 Close
11.	Krzysztof Sobucki, Paweł Gruszecki, Justyna Rychły, Maciej Krawczyk Control of the Phase of Reflected Spin Waves From Magnonic Gires–Tournois Interferometer of Subwavelength Width IEEE Transactions on Magnetics, 58 (2), pp. 1-5, 2022, ISSN: 1941-0069. Abstract \| Links \| BibTeX @article{9450803, title = {Control of the Phase of Reflected Spin Waves From Magnonic Gires–Tournois Interferometer of Subwavelength Width}, author = {Krzysztof Sobucki and Paweł Gruszecki and Justyna Rychły and Maciej Krawczyk}, doi = {10.1109/TMAG.2021.3088298}, issn = {1941-0069}, year = {2022}, date = {2022-01-20}, journal = {IEEE Transactions on Magnetics}, volume = {58}, number = {2}, pages = {1-5}, abstract = {The phase is one of the fundamental properties of a wave that allows to control interference effects and can be used to efficiently encode information. We examine numerically a magnonic resonator of the Gires–Tournois interferometer type, which enables the control of the phase of spin waves (SWs) reflected from the edge of the ferromagnetic film. The considered interferometer consists of a Py thin film and a thin, narrow Py stripe placed above its edge, both coupled magnetostatically. We show that the resonances and the phase of the reflected SWs are sensitive for a variation of the geometrical parameters of this bi-layered part of the system. The high sensitivity to film, stripe, and non-magnetic spacer thicknesses offers a prospect for developing magnonic metasurfaces and sensors.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The phase is one of the fundamental properties of a wave that allows to control interference effects and can be used to efficiently encode information. We examine numerically a magnonic resonator of the Gires–Tournois interferometer type, which enables the control of the phase of spin waves (SWs) reflected from the edge of the ferromagnetic film. The considered interferometer consists of a Py thin film and a thin, narrow Py stripe placed above its edge, both coupled magnetostatically. We show that the resonances and the phase of the reflected SWs are sensitive for a variation of the geometrical parameters of this bi-layered part of the system. The high sensitivity to film, stripe, and non-magnetic spacer thicknesses offers a prospect for developing magnonic metasurfaces and sensors. Close doi:10.1109/TMAG.2021.3088298 Close
2021
10.	Marek Vanatka, Krzysztof Szulc, Ondrej Wojewoda, Carsten Dubs, Andrii V Chumak, Maciej Krawczyk, Oleksandr V Dobrovolskiy, Jarosław W. Kłos, Michal Urbánek Spin-Wave Dispersion Measurement by Variable-Gap Propagating Spin-Wave Spectroscopy Phys. Rev. Applied, 16 , pp. 054033, 2021. Links \| BibTeX @article{PhysRevApplied.16.054033, title = {Spin-Wave Dispersion Measurement by Variable-Gap Propagating Spin-Wave Spectroscopy}, author = {Marek Vanatka and Krzysztof Szulc and Ondrej Wojewoda and Carsten Dubs and Andrii V Chumak and Maciej Krawczyk and Oleksandr V Dobrovolskiy and Jarosław W. Kłos and Michal Urbánek}, url = {https://link.aps.org/doi/10.1103/PhysRevApplied.16.054033}, doi = {10.1103/PhysRevApplied.16.054033}, year = {2021}, date = {2021-11-17}, journal = {Phys. Rev. Applied}, volume = {16}, pages = {054033}, publisher = {American Physical Society}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close https://link.aps.org/doi/10.1103/PhysRevApplied.16.054033 doi:10.1103/PhysRevApplied.16.054033 Close
9.	Anjan Barman, Gianluca Gubbiotti, S Ladak, A O Adeyeye, Maciej Krawczyk, J Gräfe, C Adelmann, S Cotofana, A Naeemi, V I Vasyuchka, B Hillebrands, S A Nikitov, H Yu, D Grundler, A V Sadovnikov, A A Grachev, S E Sheshukova, J-Y Duquesne, M Marangolo, G Csaba, W Porod, V E Demidov, S Urazhdin, S O Demokritov, E Albisetti, D Petti, R Bertacco, H Schultheiss, V V Kruglyak, V D Poimanov, S Sahoo, J Sinha, H Yang, M Münzenberg, T Moriyama, S Mizukami, P Landeros, R A Gallardo, G Carlotti, J-V Kim, R L Stamps, R E Camley, Bivas Rana, Y Otani, W Yu, T Yu, G E W Bauer, C Back, G S Uhrig, O V Dobrovolskiy, B Budinska, H Qin, S van Dijken, A V Chumak, A Khitun, D E Nikonov, I A Young, B W Zingsem, M Winklhofer The 2021 Magnonics Roadmap Journal of Physics: Condensed Matter, 33 (41), pp. 413001, 2021. Abstract \| Links \| BibTeX @article{Barman_2021, title = {The 2021 Magnonics Roadmap}, author = {Anjan Barman and Gianluca Gubbiotti and S Ladak and A O Adeyeye and Maciej Krawczyk and J Gräfe and C Adelmann and S Cotofana and A Naeemi and V I Vasyuchka and B Hillebrands and S A Nikitov and H Yu and D Grundler and A V Sadovnikov and A A Grachev and S E Sheshukova and J-Y Duquesne and M Marangolo and G Csaba and W Porod and V E Demidov and S Urazhdin and S O Demokritov and E Albisetti and D Petti and R Bertacco and H Schultheiss and V V Kruglyak and V D Poimanov and S Sahoo and J Sinha and H Yang and M Münzenberg and T Moriyama and S Mizukami and P Landeros and R A Gallardo and G Carlotti and J-V Kim and R L Stamps and R E Camley and Bivas Rana and Y Otani and W Yu and T Yu and G E W Bauer and C Back and G S Uhrig and O V Dobrovolskiy and B Budinska and H Qin and S van Dijken and A V Chumak and A Khitun and D E Nikonov and I A Young and B W Zingsem and M Winklhofer}, url = {https://doi.org/10.1088/1361-648x/abec1a}, doi = {10.1088/1361-648x/abec1a}, year = {2021}, date = {2021-08-18}, journal = {Journal of Physics: Condensed Matter}, volume = {33}, number = {41}, pages = {413001}, publisher = {IOP Publishing}, abstract = {Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Magnonics is a budding research field in nanomagnetism and nanoscience that addresses the use of spin waves (magnons) to transmit, store, and process information. The rapid advancements of this field during last one decade in terms of upsurge in research papers, review articles, citations, proposals of devices as well as introduction of new sub-topics prompted us to present the first roadmap on magnonics. This is a collection of 22 sections written by leading experts in this field who review and discuss the current status besides presenting their vision of future perspectives. Today, the principal challenges in applied magnonics are the excitation of sub-100 nm wavelength magnons, their manipulation on the nanoscale and the creation of sub-micrometre devices using low-Gilbert damping magnetic materials and its interconnections to standard electronics. To this end, magnonics offers lower energy consumption, easier integrability and compatibility with CMOS structure, reprogrammability, shorter wavelength, smaller device features, anisotropic properties, negative group velocity, non-reciprocity and efficient tunability by various external stimuli to name a few. Hence, despite being a young research field, magnonics has come a long way since its early inception. This roadmap asserts a milestone for future emerging research directions in magnonics, and hopefully, it will inspire a series of exciting new articles on the same topic in the coming years. Close https://doi.org/10.1088/1361-648x/abec1a doi:10.1088/1361-648x/abec1a Close
8.	Piotr Graczyk, Maciej Krawczyk Nonresonant amplification of spin waves through interface magnetoelectric effect and spin-transfer torque Scientific Reports, 11 (1), pp. 15692, 2021. Abstract \| Links \| BibTeX @article{graczyk_nonresonant_2021, title = {Nonresonant amplification of spin waves through interface magnetoelectric effect and spin-transfer torque}, author = {Piotr Graczyk and Maciej Krawczyk}, url = {https://www.nature.com/articles/s41598-021-95267-1}, doi = {10.1038/s41598-021-95267-1}, year = {2021}, date = {2021-08-03}, urldate = {2021-08-03}, journal = {Scientific Reports}, volume = {11}, number = {1}, pages = {15692}, abstract = {We present a new mechanism for manipulation of the spin-wave amplitude through the use of the dynamic charge-mediated magnetoelectric effect in ultrathin multilayers composed of dielectric thin-film capacitors separated by a ferromagnetic bilayer. Propagating spin waves can be amplified and attenuated with rising and decreasing slopes of the oscillating voltage, respectively, locally applied to the sample. The way the spin accumulation is generated makes the interaction of the spin-transfer torque with the magnetization dynamics mode-selective and restricted to some range of spin-wave frequencies, which is contrary to known types of the spin-transfer torque effects. The interfacial nature of spin-dependent screening allows to reduce the thickness of the fixed magnetization layer to a few nanometers, thus the proposed effect significantly contributes toward realization of the magnonic devices and also miniaturization of the spintronic devices.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close We present a new mechanism for manipulation of the spin-wave amplitude through the use of the dynamic charge-mediated magnetoelectric effect in ultrathin multilayers composed of dielectric thin-film capacitors separated by a ferromagnetic bilayer. Propagating spin waves can be amplified and attenuated with rising and decreasing slopes of the oscillating voltage, respectively, locally applied to the sample. The way the spin accumulation is generated makes the interaction of the spin-transfer torque with the magnetization dynamics mode-selective and restricted to some range of spin-wave frequencies, which is contrary to known types of the spin-transfer torque effects. The interfacial nature of spin-dependent screening allows to reduce the thickness of the fixed magnetization layer to a few nanometers, thus the proposed effect significantly contributes toward realization of the magnonic devices and also miniaturization of the spintronic devices. Close https://www.nature.com/articles/s41598-021-95267-1 doi:10.1038/s41598-021-95267-1 Close
7.	Felix Groß, Mateusz Zelent, Ajay Gangwar, Sławomir Mamica, Paweł Gruszecki, Matthias Werner, Gisela Schütz, Markus Weigand, Eberhard J Goering, Christian H Back, Maciej Krawczyk, Joachim Gräfe Phase resolved observation of spin wave modes in antidot lattices Appl. Phys. Lett., 118 (23), pp. 232403, 2021. Abstract \| Links \| BibTeX @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} } Close 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. Close https://doi.org/10.1063/5.0045142 doi:10.1063/5.0045142 Close
6.	Pierre Roberjot, Krzysztof Szulc, Jarosław W. Kłos, Maciej Krawczyk Multifunctional operation of the double-layer ferromagnetic structure coupled by a rectangular nanoresonator Appl. Phys. Lett., 118 (18), pp. 182406, 2021. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0046001b, title = {Multifunctional operation of the double-layer ferromagnetic structure coupled by a rectangular nanoresonator}, author = {Pierre Roberjot and Krzysztof Szulc and Jarosław W. Kłos and Maciej Krawczyk}, url = {https://doi.org/10.1063/5.0046001}, doi = {10.1063/5.0046001}, year = {2021}, date = {2021-05-05}, journal = {Appl. Phys. Lett.}, volume = {118}, number = {18}, pages = {182406}, abstract = {The use of spin waves as a signal carrier requires developing the functional elements allowing for multiplexing and demultiplexing information coded at different wavelengths. For this purpose, we propose a system of thin ferromagnetic layers dynamically coupled by a rectangular ferromagnetic resonator. We show that single and double, clockwise and counterclockwise, circulating modes of the resonator offer a wide possibility of control of propagating waves. Particularly, at frequency related to the double-clockwise circulating spin-wave mode of the resonator, the spin wave excited in one layer is transferred to the second one where it propagates in the backward direction. Interestingly, the wave excited in the second layer propagates in the forward direction only in that layer. This demonstrates add-drop filtering and circulator functionality. Thus, the proposed system can become an important part of future magnonic technology for signal routing.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The use of spin waves as a signal carrier requires developing the functional elements allowing for multiplexing and demultiplexing information coded at different wavelengths. For this purpose, we propose a system of thin ferromagnetic layers dynamically coupled by a rectangular ferromagnetic resonator. We show that single and double, clockwise and counterclockwise, circulating modes of the resonator offer a wide possibility of control of propagating waves. Particularly, at frequency related to the double-clockwise circulating spin-wave mode of the resonator, the spin wave excited in one layer is transferred to the second one where it propagates in the backward direction. Interestingly, the wave excited in the second layer propagates in the forward direction only in that layer. This demonstrates add-drop filtering and circulator functionality. Thus, the proposed system can become an important part of future magnonic technology for signal routing. Close https://doi.org/10.1063/5.0046001 doi:10.1063/5.0046001 Close
5.	Krzysztof Sobucki, Wojciech Śmigaj, Justyna Rychły, Maciej Krawczyk, Paweł Gruszecki Resonant subwavelength control of the phase of spin waves reflected from a Gires–Tournois interferometer Sci. Rep., 11 (1), pp. 4428, 2021, ISSN: 2045-2322. Abstract \| Links \| BibTeX @article{sobucki_resonant_2021, title = {Resonant subwavelength control of the phase of spin waves reflected from a Gires–Tournois interferometer}, author = {Krzysztof Sobucki and Wojciech Śmigaj and Justyna Rychły and Maciej Krawczyk and Paweł Gruszecki}, url = {https://www.nature.com/articles/s41598-021-83307-9}, doi = {10.1038/s41598-021-83307-9}, issn = {2045-2322}, year = {2021}, date = {2021-02-24}, urldate = {2021-02-25}, journal = {Sci. Rep.}, volume = {11}, number = {1}, pages = {4428}, abstract = {Subwavelength resonant elements are essential building blocks of metamaterials and metasurfaces, which have revolutionized photonics. Despite similarities between different wave phenomena, other types of interactions can make subwavelength coupling significantly distinct; its investigation in their context is therefore of interest both from the physics and applications perspective. In this work, we demonstrate a fully magnonic Gires–Tournois interferometer based on a subwavelength resonator made of a narrow ferromagnetic stripe lying above the edge of a ferromagnetic film. The bilayer formed by the stripe and the film underneath supports two propagative spin-wave modes, one strongly coupled with spin waves propagating in the rest of the film and another almost completely reflected at the ends of the bilayer. When the Fabry–Perot resonance conditions for this mode are satisfied, the weak coupling between both modes is sufficient to achieve high sensitivity of the phase of waves reflected from the resonator to the stripe width and, more interestingly, also to the stripe-film separation. Such spin-wave phase manipulation capabilities are a prerequisite for the design of spin-wave metasurfaces and may stimulate development of magnonic logic devices and sensors detecting magnetic nanoparticles.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Subwavelength resonant elements are essential building blocks of metamaterials and metasurfaces, which have revolutionized photonics. Despite similarities between different wave phenomena, other types of interactions can make subwavelength coupling significantly distinct; its investigation in their context is therefore of interest both from the physics and applications perspective. In this work, we demonstrate a fully magnonic Gires–Tournois interferometer based on a subwavelength resonator made of a narrow ferromagnetic stripe lying above the edge of a ferromagnetic film. The bilayer formed by the stripe and the film underneath supports two propagative spin-wave modes, one strongly coupled with spin waves propagating in the rest of the film and another almost completely reflected at the ends of the bilayer. When the Fabry–Perot resonance conditions for this mode are satisfied, the weak coupling between both modes is sufficient to achieve high sensitivity of the phase of waves reflected from the resonator to the stripe width and, more interestingly, also to the stripe-film separation. Such spin-wave phase manipulation capabilities are a prerequisite for the design of spin-wave metasurfaces and may stimulate development of magnonic logic devices and sensors detecting magnetic nanoparticles. Close https://www.nature.com/articles/s41598-021-83307-9 doi:10.1038/s41598-021-83307-9 Close
4.	Paweł Gruszecki, Igor L. Lyubchanskii, Konstantin Y Guslienko, Maciej Krawczyk Local non-linear excitation of sub-100 nm bulk-type spin waves by edge-localized spin waves in magnetic films Appl. Phys. Lett., 118 (6), pp. 062408, 2021. Abstract \| Links \| BibTeX @article{doi:10.1063/5.0041030, title = {Local non-linear excitation of sub-100 nm bulk-type spin waves by edge-localized spin waves in magnetic films}, author = {Paweł Gruszecki and Igor L. Lyubchanskii and Konstantin Y Guslienko and Maciej Krawczyk}, doi = {10.1063/5.0041030}, year = {2021}, date = {2021-02-11}, journal = {Appl. Phys. Lett.}, volume = {118}, number = {6}, pages = {062408}, abstract = {The excitation of high-frequency short-wavelength spin waves is a challenge limiting the application of these propagating magnetization disturbances in information processing systems. We propose a method of local excitation of the high-frequency spin waves using the non-linear nature of magnetization dynamics. We demonstrate with numeric simulations that an edge-localized spin wave can be used to excite plane waves propagating obliquely from the film's edge at a doubled frequency and over twice shorter in wavelength. The excitation mechanism is a direct result of the ellipticity of the magnetic moment precession that is related to the edge-mode propagation. As a consequence, the magnetization component tangential to the equilibrium orientation oscillates with doubled temporal and spatial frequencies, which leads to efficient excitation of the plane spin waves. The threshold-less non-linear process of short-wavelength spin-wave excitation proposed in our study is promising for integration with an inductive or point-like spin-torque source of edge spin waves. The research leading to these results received funding from the National Science Centre of Poland, Project No. 2019/35/D/ST3/03729. I.L.L. acknowledges support from a COST action under Project No. CA17123 MAGNETOFON. K.Y.G. acknowledges support from IKERBASQUE (the Basque Foundation for Science) and from the Spanish Ministerio de Ciencia, Innovacion y Universidades Grant No. PID2019-108075RB-C33/AEI/10.13039/501100011033. The simulations were partially performed at the Poznan Supercomputing and Networking Center (Grant No. 398).}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The excitation of high-frequency short-wavelength spin waves is a challenge limiting the application of these propagating magnetization disturbances in information processing systems. We propose a method of local excitation of the high-frequency spin waves using the non-linear nature of magnetization dynamics. We demonstrate with numeric simulations that an edge-localized spin wave can be used to excite plane waves propagating obliquely from the film's edge at a doubled frequency and over twice shorter in wavelength. The excitation mechanism is a direct result of the ellipticity of the magnetic moment precession that is related to the edge-mode propagation. As a consequence, the magnetization component tangential to the equilibrium orientation oscillates with doubled temporal and spatial frequencies, which leads to efficient excitation of the plane spin waves. The threshold-less non-linear process of short-wavelength spin-wave excitation proposed in our study is promising for integration with an inductive or point-like spin-torque source of edge spin waves. The research leading to these results received funding from the National Science Centre of Poland, Project No. 2019/35/D/ST3/03729. I.L.L. acknowledges support from a COST action under Project No. CA17123 MAGNETOFON. K.Y.G. acknowledges support from IKERBASQUE (the Basque Foundation for Science) and from the Spanish Ministerio de Ciencia, Innovacion y Universidades Grant No. PID2019-108075RB-C33/AEI/10.13039/501100011033. The simulations were partially performed at the Poznan Supercomputing and Networking Center (Grant No. 398). Close doi:10.1063/5.0041030 Close
3.	Jarosław W. Kłos, Igor L. Lyubchanskii, Maciej Krawczyk, Paweł Gruszecki, Szymon Mieszczak, Justyna Rychły, Yuliya S. Dadoenkova, Nataliya N. Dadoenkova Magnonics and Confinement of Light in Photonic–Magnonic Crystals, in Optomagnonic Structures Almpanis, Evangelos (Ed.): Chapter 2, pp. 79–134, World Scientific Publishing, Singapure, 2021, ISBN: 978-981-122-005-0. Abstract \| Links \| BibTeX @inbook{opto-mag, title = {Magnonics and Confinement of Light in Photonic–Magnonic Crystals, in Optomagnonic Structures}, author = {Jarosław W. Kłos and Igor L. Lyubchanskii and Maciej Krawczyk and Paweł Gruszecki and Szymon Mieszczak and Justyna Rychły and Yuliya S. Dadoenkova and Nataliya N. Dadoenkova}, editor = {Evangelos Almpanis}, doi = {10.1142/9789811220050_0002}, isbn = {978-981-122-005-0}, year = {2021}, date = {2021-02-08}, pages = {79–134}, publisher = {World Scientific Publishing}, address = {Singapure}, chapter = {2}, abstract = {We discuss the spin-wave confinement in the magnetic components of magnetophotonic structures. In the initial sections of the chapter, we describe the principles of magnetization dynamics, including both the exchange and dipolar interactions. We showed that the spin-wave spectrum in confined geometry is determined not only by the spatial constraints but is also strongly influenced by non-local demagnetizing effects. In addition, we analyze the localization of light in the regions of spin-wave confinement, which can strengthen the magneto–optical interaction. Such enhancement can be potentially realized in photonic–magnonic crystals, where the light localization in magnetic components of the structure results from the periodicity and the spin waves co-exist with electromagnetic waves. The final sections are devoted to the Faraday effect and Goos–Hänchen effect in photonic–magnonic crystals.}, keywords = {}, pubstate = {published}, tppubtype = {inbook} } Close We discuss the spin-wave confinement in the magnetic components of magnetophotonic structures. In the initial sections of the chapter, we describe the principles of magnetization dynamics, including both the exchange and dipolar interactions. We showed that the spin-wave spectrum in confined geometry is determined not only by the spatial constraints but is also strongly influenced by non-local demagnetizing effects. In addition, we analyze the localization of light in the regions of spin-wave confinement, which can strengthen the magneto–optical interaction. Such enhancement can be potentially realized in photonic–magnonic crystals, where the light localization in magnetic components of the structure results from the periodicity and the spin waves co-exist with electromagnetic waves. The final sections are devoted to the Faraday effect and Goos–Hänchen effect in photonic–magnonic crystals. Close doi:10.1142/9789811220050_0002 Close
2.	Nick Träger, Paweł Gruszecki, Filip Lisiecki, Felix Groß, Johannes Förster, Markus Weigand, Hubert Głowiński, Piotr Kuświk, Janusz Dubowik, Gisela Schütz, Maciej Krawczyk, Joachim Gräfe Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals Phys. Rev. Lett., 126 , pp. 057201, 2021. Abstract \| Links \| BibTeX @article{PhysRevLett.126.057201, title = {Real-Space Observation of Magnon Interaction with Driven Space-Time Crystals}, author = {Nick Träger and Paweł Gruszecki and Filip Lisiecki and Felix Groß and Johannes Förster and Markus Weigand and Hubert Głowiński and Piotr Kuświk and Janusz Dubowik and Gisela Schütz and Maciej Krawczyk and Joachim Gräfe}, url = {https://doi.org/10.1103/PhysRevLett.126.057201}, doi = {10.1103/PhysRevLett.126.057201}, year = {2021}, date = {2021-02-03}, journal = {Phys. Rev. Lett.}, volume = {126}, pages = {057201}, abstract = {The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC’s Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close The concept of space-time crystals (STC), i.e., translational symmetry breaking in time and space, was recently proposed and experimentally demonstrated for quantum systems. Here, we transfer this concept to magnons and experimentally demonstrate a driven STC at room temperature. The STC is realized by strong homogeneous microwave pumping of a micron-sized permalloy (Py) stripe and is directly imaged by scanning transmission x-ray microscopy (STXM). For a fundamental understanding of the formation of the STC, micromagnetic simulations are carefully adapted to model the experimental findings. Beyond the mere generation of a STC, we observe the formation of a magnonic band structure due to back folding of modes at the STC’s Brillouin zone boundaries. We show interactions of magnons with the STC that appear as lattice scattering, which results in the generation of ultrashort spin waves (SW) down to 100-nm wavelengths that cannot be described by classical dispersion relations for linear SW excitation. We expect that room-temperature STCs will be useful to investigate nonlinear wave physics, as they can be easily generated and manipulated to control their spatial and temporal band structures. Close https://doi.org/10.1103/PhysRevLett.126.057201 doi:10.1103/PhysRevLett.126.057201 Close
1.	Nick Träger, Filip Lisiecki, Robert Lawitzki, Markus Weigand, Hubert Głowiński, Gisela Schütz, Guido Schmitz, Piotr Kuświk, Maciej Krawczyk, Joachim Gräfe, Paweł Gruszecki Competing spin wave emission mechanisms revealed by time-resolved x-ray microscopy Phys. Rev. B, 103 , pp. 014430, 2021. Abstract \| Links \| BibTeX @article{PhysRevB.103.014430, title = {Competing spin wave emission mechanisms revealed by time-resolved x-ray microscopy}, author = {Nick Träger and Filip Lisiecki and Robert Lawitzki and Markus Weigand and Hubert Głowiński and Gisela Schütz and Guido Schmitz and Piotr Kuświk and Maciej Krawczyk and Joachim Gräfe and Paweł Gruszecki}, url = {https://link.aps.org/doi/10.1103/PhysRevB.103.014430}, doi = {10.1103/PhysRevB.103.014430}, year = {2021}, date = {2021-01-19}, journal = {Phys. Rev. B}, volume = {103}, pages = {014430}, publisher = {American Physical Society}, abstract = {Spin wave emission and propagation in magnonic waveguides represent a highly promising alternative for beyond-CMOS computing. It is therefore all the more important to fully understand the underlying physics of the emission process. Here, we use time-resolved scanning transmission x-ray microscopy to directly image the formation process of the globally excited local emission of spin waves in a permalloy waveguide at the nanoscale. Thereby, we observe spin wave emission from the corner of the waveguide as well as from a local oscillation of a domain-wall-like structure within the waveguide. Additionally, an isofrequency contour analysis is used to fully explain the origin of quasicylindrical spin wave excitation from the corner and its concurrent nonreflection and nonrefraction at the domain interface. This study is complemented by micromagnetic simulations which perfectly fit the experimental findings. Thus, we clarify the fundamental question of the emission mechanisms in magnonic waveguides which lay the basis for future magnonic operations.}, keywords = {}, pubstate = {published}, tppubtype = {article} } Close Spin wave emission and propagation in magnonic waveguides represent a highly promising alternative for beyond-CMOS computing. It is therefore all the more important to fully understand the underlying physics of the emission process. Here, we use time-resolved scanning transmission x-ray microscopy to directly image the formation process of the globally excited local emission of spin waves in a permalloy waveguide at the nanoscale. Thereby, we observe spin wave emission from the corner of the waveguide as well as from a local oscillation of a domain-wall-like structure within the waveguide. Additionally, an isofrequency contour analysis is used to fully explain the origin of quasicylindrical spin wave excitation from the corner and its concurrent nonreflection and nonrefraction at the domain interface. This study is complemented by micromagnetic simulations which perfectly fit the experimental findings. Thus, we clarify the fundamental question of the emission mechanisms in magnonic waveguides which lay the basis for future magnonic operations. Close https://link.aps.org/doi/10.1103/PhysRevB.103.014430 doi:10.1103/PhysRevB.103.014430 Close