Reconfigurable 3D magnonic crystal: tunable and localized spin-wave excitations in CoFeB meander-shaped film
A. V. Sadovnikov, G. Talmelli, G. Gubbiotti, E. N. Beginin, S. Sheshukova, S. A. Nikitov, C. Adelmann, F. Ciubotaru
备注：
This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No. 801055 "Spin Wave Computing for Ultimately-Scaled Hybrid Low-Power Electronics" CHIRON
In this work, we study experimentally by broadband ferromagnetic resonance measurements, the dependence of the spin-wave excitation spectra on the magnetic applied field in CoFeB meander-shaped films. Two different orientations of the external magnetic field were explored, namely parallel or perpendicular to the lattice cores. The interpretation of the field dependence of the frequency and spatial profiles of major spin-wave modes were obtained by micromagnetic simulations. We show that the vertical segments lead to the easy-axis type of magnetic anisotropy and support the in-phase and out-of-phase spin-wave precession amplitude in the vertical segments. The latter could potentially be used for the design of tunable metasurfaces or in magnetic memories based on meandering 3D magnetic films.
In this work, we investigate the spin-wave propagation in three-dimensional nanoscale CoFeB/Ta/NiFe meander structures fabricated on a structured SiO2/Si substrate. The magnonic band structure has been experimentally determined by wavevector-resolved Brillouin light scattering (BLS) spectroscopy and a set of stationary modes interposed by two dispersive modes of Bloch type have been identified. The results could be understood by micromagnetic and finite element simulations of the mode distributions in both real space and the frequency domain. The dispersive modes periodically oscillate in freq…
We report on the excitation and detection of short-waved spin waves with wave vectors up to about $40\,\mathrm{rad}\,μ\mathrm{m}^{-1}$ in spin-wave waveguides made from ultrathin, in-plane magnetized Co$_{8}$Fe$_{72}$B$_{20}$ (CoFeB). The CoFeB is incorporated in a layer stack of Ta/CoFeB/Mgo, a layer system featuring large spin orbit torques and a large perpendicular magnetic anisotropy constant. The short-waved spin waves are excited by nanometric coplanar waveguides and are detected via spin rectification and microfocussed Brillouin light scattering spectroscopy. We show that the large perp…
The dispersion of spin waves in vertical meander-shaped CoFeB thin films consisting of segments located at 90° angles with respect to each other is investigated by Brillouin light scattering spectroscopy. We reveal the periodic character of several dispersive branches as well as alternating frequency ranges where spin waves are allowed or forbidden to propagate. Noteworthy is the presence of the frequency band gaps between each couple of successive modes only for wave numbers k=n$π$/a, where n is an even integer number and a is the size of the meander unit cell, whereas the spectra show propag…
Electric-field controlled magnetization dynamics is an important integrant in low power spintronic devices. In this letter, we demonstrate electric-field induced parametric excitation for CoFeB/MgO junctions by using interfacial in-plane magnetic anisotropy. When the in-plane magnetic anisotropy and the external magnetic field are parallel to each other, magnons are efficiently excited by using electric-field induced parametric excitation. Its wavelength and wavenumber are tuned by changing input power and frequency of the applied voltage. A generalized phenomenological model is developed to e…
Estimation of spin-orbit torques in the presence of current-induced magnon creation and annihilation
Université de Strasbourg, CNRS, Institut de Physique et Chimie des Matériaux de Strasbourg（斯特拉斯堡大学，法国国家科学研究中心，斯特拉斯堡材料与化学物理研究所）；ETH Zurich（苏黎世联邦理工学院）；Politecnico di Milano（米兰理工大学）
Spin currents offer a way to control static and dynamic magnetic properties, and therefore they are crucial for next-generation MRAM devices or spin-torque oscillators. Manipulating the dynamics is especially interesting within the context of photo-magnonics. In typical $3d$ transition metal ferromagnets like CoFeB, the lifetime of light-induced magnetization dynamics is restricted to about 1 ns, which e.g. strongly limits the opportunities to exploit the wave nature in a magnonic crystal filtering device. Here, we investigate the potential of spin-currents to increase the spin wave lifetime i…
Frequency-Division Multiplexing in Magnonic Waveguides
National Institute of Research and Development in Microtechnologies - IMT Bucharest（布加勒斯特微技术国家研究与开发研究所）；Department of Physics, Alexandru Ioan Cuza University（亚历山德鲁·约安·库扎大学物理系）；Imec；National University of Science and Technology POLITEHNICA Bucharest（布加勒斯特国立科技大学）
Magnonics is seen nowadays as a candidate technology for energy-efficient data processing in classical and quantum systems. Pronounced nonlinearity, anisotropy of dispersion relations and phase degree of freedom of spin waves require advanced methodology for probing spin waves at room as well as at mK temperatures. Yet, the use of the established optical techniques like Brillouin light scattering (BLS) or magneto optical Kerr effect (MOKE) at ultra-low temperatures is forbiddingly complicated. By contrast, microwave spectroscopy can be used at all temperatures but is usually lacking spatial an…
Active manipulation of spin waves is essential for the development of magnon-based technologies. Here, we demonstrate programmable spin-wave filtering by resetting the spin structure of a pinned 90$^\circ$ Néel domain wall in a continuous CoFeB film with abrupt rotations of uniaxial magnetic anisotropy. Using phase-resolved micro-focused Brillouin light scattering and micromagnetic simulations, we show that broad 90$^\circ$ head-to-head or tail-to-tail magnetic domain walls are transparent to spin waves over a broad frequency range. In contrast, magnetic switching to a 90$^\circ$ head-to-tail …
A strategy for a scalable synchronization of an array of spin-Hall oscillators (SHOs) is illustrated. In detail, we present micromagnetic simulations of two and five SHOs realized by means of couples of triangular golden contacts on the top of a Pt/CoFeB/Ta trilayer. Results highlight that the synchronization occurs for the whole current region that gives rise to the excitation of self-oscillations. This is linked to the role of the magnetodipolar coupling, which is the phenomenon driving the synchronization when the distance between oscillators is not too large. Synchronization turns out to b…
Micromagnetic Modeling of Surface Acoustic Wave Driven Dynamics: Interplay of Strain, Magnetorotation, and Magnetic Anisotropy
Sorbonne Université（索邦大学）；CNRS（法国国家科学研究中心）；Institut des Nanosciences de Paris（巴黎纳米科学研究所）；Université de Strasbourg（斯特拉斯堡大学）；Institut de Physique et Chimie des Matériaux de Strasbourg（斯特拉斯堡材料与物理化学研究所）
Controlling Skyrmion Lattice Orientation with Local Magnetic Field Gradients
Institute of Physics, Johannes Gutenberg University Mainz（约翰内斯·古腾堡大学美因茨分校物理研究所）；Department of Physics and Materials Science, University of Luxembourg（卢森堡大学物理与材料科学系）；Department of Materials Science and Engineering, Norwegian University of Science and Technology (NTNU)（挪威科技大学材料与工程系）；Centre for Quantum Spintronics, Norwegian University of Science and Technology (NTNU)（挪威科技大学量子自旋电子学中心）；Faculty of Physics, University of Duisburg-Essen（杜伊斯堡-埃森大学物理学院）
