A5000563234- Magnetic properties of thin films
- Magneto-Optical Properties and Applications
- Quantum and electron transport phenomena
- Magnetic Properties and Applications
- Physics of Superconductivity and Magnetism
- Advanced Electron Microscopy Techniques and Applications
- Ion-surface interactions and analysis
- Characterization and Applications of Magnetic Nanoparticles
- Optical Coatings and Gratings
- Mechanical and Optical Resonators
- Electron and X-Ray Spectroscopy Techniques
- ZnO doping and properties
- Photonic and Optical Devices
- Surface and Thin Film Phenomena
- Force Microscopy Techniques and Applications
- Atomic and Subatomic Physics Research
- Semiconductor materials and devices
- Photoacoustic and Ultrasonic Imaging
- Magnetic Field Sensors Techniques
- Microstructure and mechanical properties
- Surface Roughness and Optical Measurements
- Thin-Film Transistor Technologies
- Quantum optics and atomic interactions
- Nanomaterials for catalytic reactions
- Catalytic Processes in Materials Science
Brno University of Technology
2016-2025
Central European Institute of Technology
2016-2025
Spin waves are ideal candidates for wave-based computing, but the construction of magnetic circuits is blocked by a lack an efficient mechanism to excite long-running exchange spin with normalized amplitudes. Here, we solve challenge exploiting deeply nonlinear phenomenon forward volume in 200-nm-wide nanoscale waveguides and validate our concept using microfocused Brillouin light scattering spectroscopy. An unprecedented frequency shift more than 2 GHz achieved, corresponding magnetization...
Skyrmions and antiskyrmions are topologically protected spin structures with opposite topological charge. Particularly in coexisting phases, these two types of magnetic quasi-particles may show fascinating physics potential for spintronic devices. While skyrmions observed a wide range materials, until now were exclusive to materials D2d symmetry. In this work, we first second-order stabilized by dipole-dipole interaction Fe/Gd-based multilayers. We modify the properties multilayers Ir...
Performing propagating spin-wave spectroscopy of thin films at millikelvin temperatures is the next step toward realization large-scale integrated magnonic circuits for quantum applications. Here, we demonstrate propagation in a 100 nm-thick yttrium-iron-garnet (YIG) film down to 45 mK, using stripline nanoantennas deposited on YIG surface electrical excitation and detection. The clear transmission characteristics over distance 10 μ m are measured extracted group velocity saturation...
Abstract Quantum magnonics investigates the quantum-mechanical properties of magnons, such as quantum coherence or entanglement for solid-state information technologies at nanoscale. The most promising material is ferrimagnetic yttrium iron garnet (YIG), which hosts magnons with longest lifetimes. YIG films highest quality are grown on a paramagnetic gadolinium gallium (GGG) substrate. literature has reported that ferromagnetic resonance (FMR) frequencies YIG/GGG decrease temperatures below...
Abstract Local probing of dynamic excitations such as magnons and phonons in materials nanostructures can bring new insights into their properties functionalities. For example, magnonics, many concepts devices recently demonstrated at the macro- microscale now need to be realized nanoscale. Brillouin light scattering (BLS) spectroscopy microscopy has become a standard technique for spin wave characterization, enabled pioneering magnonic experiments. However, conventional BLS cannot detect...
We studied the influence of a static in-plane magnetic field on alternating-field-driven emission nanoscale spin waves from vortex cores. Time-resolved scanning transmission X-ray microscopy was used to image in disk structures synthetic ferrimagnets and single ferromagnetic layers. For both systems, it found that an increasing bias continuously displaces wave-emitting core center toward its edge without noticeably altering spin-wave dispersion relation. In case single-layer disk,...
The maximal speed ${v}^{\ensuremath{\ast}}$ for magnetic flux quanta is determined by the energy relaxation of unpaired electrons and thus essential superconducting microstrip single-photon detectors (SMSPDs). However, deduction from current-voltage ($I$-$V$) curves at zero field hindered unknown number vortices, ${n}_{v}$, as a small fast-moving vortices can induce same voltage large slow-moving ones. Here, we introduce an approach quantitative determination ${n}_{v}$...
We report on experimental observation of unidirectional propagation zero-momentum magnons in synthetic antiferromagnet consisting strained CoFeB/Ru/CoFeB trilayer. Inherent non-reciprocity spin waves antiferromagnets with uniaxial anisotropy results smooth and monotonous dispersion relation around Gamma point, where the direction phase velocity is reversed, while group conserved. The this phenomenon by intensity-, phase-, time-resolved Brillouin light scattering microscopy corroborated...
Knowledge of the spin-wave dispersion relation is a prerequisite for explanation many magnonic phenomena as well practical design devices. Spin-wave measurement by established optical techniques such Brillouin light scattering or magneto-optical Kerr effect at ultralow temperatures often forbiddingly complicated. By contrast, microwave spectroscopy can be used all but it usually lacks spatial and wave-number resolution. Here we develop variable-gap-propagating-spin-wave-spectroscopy (VGPSWS)...
Focused ion beam irradiation of metastable Fe$_{78}$Ni$_{22}$ thin films grown on Cu(100) substrates is used to create ferromagnetic, body-centered-cubic patterns embedded into paramagnetic, face-centered-cubic surrounding. The structural and magnetic phase transformation can be controlled by varying parameters the transforming gallium beam. focused as dose, number scans, scanning direction not only control a degree transformation, but also change otherwise four-fold in-plane anisotropy...
Spin waves have the potential to be used as a next-generation platform for data transfer and processing they can reach wavelengths in nanometer range frequencies terahertz range. To realize spin-wave device, it is essential able manipulate amplitude well phase of spin waves. Several theoretical recent experimental works also shown that manipulated by transmission through domain wall (DW). Here, we study propagation DW means micro-focused Brillouin light scattering microscopy (μBLS). The 2D...
Modern quantum technologies and hybrid systems offer the opportunity to utilize magnons on level of single excitations. Long lifetimes, low decoherence rates, a strong coupling rate other subsystems propose ferrimagnet yttrium iron garnet (YIG), grown gadolinium gallium (GGG) substrate, as suitable platform host magnonic states. However, magnetic damping at cryogenic temperatures significantly increases due paramagnetic character highly inhomogeneous stray field GGG, recent experiments...
Magnons, the quanta of spin waves, are magnetic excitations matter spanning through entire crystal's Brillouin zone and covering a wide range frequencies ranging from sub-gigahertz to hundreds terahertz. Magnons play crucial role in many condensed phenomena, such as reduction saturation magnetization with increasing temperature or Bose-Einstein condensation. However, current experimental techniques cannot resolve magnons wavevectors between 30 300$\,$rad$\,\mu$m$^{-1}$. In this letter, we...
Power limiters are essential devices in modern rf communication systems to protect highly sensitive input channels from large incoming signals. Nowadays-used semiconductor suffer high electronic noise and switching delays when approaching the GHz range, which is crucial for generation of 5G technologies aiming operate at EU band (24.25–27.5 GHz). The proposed solution use ferrite-based frequency selective (FSLs), maintain their efficiency frequencies, although they have only been studied...
Modern quantum technologies and hybrid systems offer the opportunity to utilize magnons on level of single excitations. Long lifetimes, low decoherence rates, a strong coupling rate other subsystems propose ferrimagnet yttrium iron garnet (YIG), grown gadolinium gallium (GGG) substrate, as suitable platform host magnonic states. However, magnetic damping at cryogenic temperatures significantly increases due paramagnetic character highly inhomogeneous stray field GGG, recent experiments...
Focused ion beam (FIB) milling has been used to fabricate magnetic nanostructures (wires, squares, discs) from single layers (Co, permalloy) and spin-valve (permalloy/Cu/Co) multilayers (thicknesses 5–50 nm) prepared by sputtering deposition. Milled surfaces of metallic thin films typically exhibit residual roughness, which is also transferred onto the edges milled patterns. This can lead domain wall pinning influence magnetization behaviour nanostructures. We have investigated process FIB...
We have used time-resolved x-ray photoemission electron microscopy to investigate the magnetization dynamics induced by nanosecond current pulses in NiFe/Cu/Co nanostripes. A large tilt of NiFe direction transverse stripe is observed during pulses. show that this effect cannot be quantitatively understood from amplitude Oersted field and shape anisotropy. High-frequency oscillations at onset are attributed precessional motion about effective field. discuss possible origins potential...
Metastable face-centered-cubic $\mathrm{F}{\mathrm{e}}_{78}\mathrm{N}{\mathrm{i}}_{22}$ thin films are excellent candidates for focused ion beam direct writing of magnonic structures due to their favorable magnetic properties after ion-beam-induced transformation. The transforms the originally nonmagnetic fcc phase into ferromagnetic bcc with additional control over direction uniaxial in-plane anisotropy and saturation magnetization. Local eliminates need external fields, paving way towards...