A5011062287- Physics of Superconductivity and Magnetism
- Magnetic properties of thin films
- Advanced Condensed Matter Physics
- Quantum and electron transport phenomena
- Topological Materials and Phenomena
- Particle Accelerators and Free-Electron Lasers
- Wood Treatment and Properties
- Natural Fiber Reinforced Composites
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced X-ray Imaging Techniques
- Lignin and Wood Chemistry
- Iron-based superconductors research
- Electronic and Structural Properties of Oxides
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Surface Roughness and Optical Measurements
- Flame retardant materials and properties
- Photonic and Optical Devices
- Multiferroics and related materials
- Phase Change Materials Research
- Quantum many-body systems
- Solar Thermal and Photovoltaic Systems
- Carbon Nanotubes in Composites
- Adsorption and Cooling Systems
- Graphene research and applications
Forschungszentrum Jülich
2018-2024
University of Göttingen
2018-2024
Jülich Aachen Research Alliance
2022
Deutsches Elektronen-Synchrotron DESY
2020
RWTH Aachen University
2015-2020
TU Dortmund University
2002
Magnetic interactions underpin a plethora of magnetic states matter, hence playing central role both in fundamental physics and for future spintronic quantum computation devices. The Dzyaloshinskii-Moriya interaction, being chiral driven by relativistic effects, leads to the stabilization highly-noncollinear spin textures such as skyrmions, which thanks their topological nature are promising building blocks data storage processing elements. Here, we reveal study new pair is biquadratic...
Abstract Chains of magnetic atoms with either strong spin-orbit coupling or spiral order which are proximity-coupled to superconducting substrates can host topologically non-trivial Majorana bound states. The experimental signature these states consists spectral weight at the Fermi energy is spatially localized near ends chain. However, trivial Yu-Shiba-Rusinov in-gap chain lead similar spectra. Here, we explore a protocol disentangle contributions by artificially augmenting candidate spin...
Spin chains proximitized with superconducting condensates have emerged as one of the most promising platforms for realization Majorana modes. Here, we craft diluted spin atom by following a seminal theoretical proposal suggesting indirect coupling mechanisms viable route to trigger topological superconductivity. Starting from single adatoms hosting deep Shiba states, use highly anisotropic Fermi surface substrate create characterized different magnetic configurations along distinct...
Atomistic spin models have found enormous success in addressing the properties of magnetic materials, grounded on identification relevant underlying interactions. The huge development field skyrmions and other noncollinear structures is largely due to our understanding chiral Dzyaloshinskii-Moriya interaction. Recently, various works proposed new types interactions, with seemingly different forms, but big picture still missing. Here, we present a systematic construction generalized model...
Abstract Interfacing magnetism with superconducting condensates is rapidly emerging as a viable route for the development of innovative quantum technologies. In this context, rational design strategies to controllably tune interaction between magnetic moments crucial. Here we address problem demonstrating possibility tuning local spins coupled through condensate atomic scale precision. By using Cr atoms Nb, use manipulation techniques precisely control relative distance along distinct...
Adding reticulated basalt fibres to wood-based panels as reinforcing materials can improve their strength-to-weight ratio and thus increase material efficiency. This study investigates the effect of different surface modifications on adhesion with binders commonly used in panel industry. The coatings were an acrylate polymer, ureido-silane a combination both conjunction urea-formaldehyde (UF), melamine-urea-formaldehyde (MUF), phenol-formaldehyde (PF), phenol-melamine-formaldehyde (PMF)...
Abstract Local spins coupled to superconductors give rise several emerging phenomena directly linked the competition between Cooper pair formation and magnetic exchange. These effects are generally scrutinized using a spectroscopic approach which relies on detecting in-gap bound modes arising from breaking, so-called Yu-Shiba-Rusinov (YSR) states. However, impact of local impurities superconducting order parameter remains largely unexplored. Here, we use scanning Josephson spectroscopy...
We present a study on the uniformity of pseudomagnetic field in graphene as function relative orientation between lattice and straining directions. For this, we strained regular micron-sized hexagon by deforming it symmetrically displacing three its edges. By simulations, found that is strongest if strain applied perpendicular to armchair direction graphene. with side length 1 ${\rm \mu}$m, has maximum 1.2 T for an 3.5% uniform (variance $< 1$%) within circle diameter $\sim 520$ nm. This...
Abstract Antiferromagnetic (AFM) skyrmions are envisioned as ideal localized topological magnetic bits in future information technologies. In contrast to ferromagnetic (FM) skyrmions, they immune the skyrmion Hall effect, might offer potential terahertz dynamics while being insensitive external fields and dipolar interactions. Although observed synthetic AFM structures complex meronic textures intrinsic bulk materials, their realization non-synthetic films, of crucial importance racetrack...
The spin of a single atom adsorbed on substrate is promising building block for future spintronics and quantum computation schemes. To process information also increased magnetic stability, these blocks have to be coupled. For atom, high symmetry the environment known lead stability. However, little about role nature couplings. Here, we study arrays atomic spins coupled via ubiquitous Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, focusing its two anisotropic parts: Dzyaloshinskii-Moriya...
There is currently a strong need to understand noncollinear magnetic phases where generalized chiral interactions can play prominent role. Here, the authors give clear and accessible discussion of improper how they arise from proper isotropic or interactions. For example, energy landscape magnets with degeneracy be mistakenly interpreted in terms large Dzyaloshinskii-Moriya that fact originate biquadratic
High–energy resolution spectroscopic studies of quantum magnets proved extremely valuable in accessing magnetodynamics quantities, such as energy barriers, magnetic interactions, and lifetime excited states. Here, we investigate a previously unexplored flavor low-energy spin excitations for spins coupled to an electron bath. In sharp contrast the usual tunneling signature two steps symmetrically centered around Fermi level, find single step conductance. Combining time-dependent many-body...
Abstract Interfacing magnetism with superconductivity gives rise to a wonderful playground for intertwining key degrees of freedom: Cooper pairs, spin, charge, and spin–orbit interaction, from which emerge wealth exciting phenomena, fundamental in the nascent field superconducting spinorbitronics topological quantum technologies. Magnetic exchange interactions (MEIs), being isotropic or chiral such as Dzyaloshinskii–Moriya interactions, are vital establishing magnetic behavior at these...
We propose a systematic and sequential expansion of the Landau-Lifshitz-Gilbert equation utilizing dependence Gilbert damping tensor on angle between magnetic moments, which arises from multi-body scattering processes. The consists damping-like term correction to gyromagnetic ratio. Based electronic structure theory, both terms are shown depend e.g. scalar, anisotropic, vector-chiral scalar-chiral products moments:ei⋅ej, (nij⋅ei)(nij⋅ej),nij⋅ (ei×ej),(ei⋅ej)2,ei⋅ (ej×ek) …, where some...
Harnessing the spin of single atoms is at heart quantum information nanotechnology based on magnetic concepts. By attaching Co to monatomic Cu chains, we demonstrate ability control orientation by atomic environment. Due spin-orbit coupling (SOC), tilted ≈58° from surface normal toward chain as evidenced inelastic tunneling spectroscopy. These findings are reproduced density functional theory calculations and have implications for pristine Cu(111), which believed be Kondo systems. Our Monte...
Abstract Flame retardants and other additives can reduce the performance of adhesives used to produce wood-based panels such as particleboards (PB). Basalt reinforcement was evaluated compensate for loss bending strength allow be in construction sector. A basalt grid with a grammage 200 g m −2 reinforce PB containing 15 m% nitrogen-phosphate based flame retardant. The modulus rupture (MOR) elasticity (MOE) reinforced were higher (69% 24%, respectively) than those corresponding reference...
This study presents an unexplored method to produce formaldehyde-free MDF. Steam exploded Arundo donax L. (STEX-AD) and untreated wood fibers (WF) were mixed at different mixing rates (0/100, 50/50, 100/0, respectively) two series of boards manufactured, with 4 wt% pMDI, based on dry fibers, self-bonded. The mechanical physical performance the was analyzed as a function adhesive content density. dimensional stability determined by following European standards. material formulation density...
In our previous Letter [Phys. Rev. B 103, L140408 (2021)], we presented a discussion of the fundamental physical properties interactions parametrizing atomistic spin models in connection to first-principles approaches that enable their calculation for given material. This explained how some those can apparently lead magnetic do not comply with expected properties, such as Dzyaloshinskii-Moriya which are nonchiral and independent spin-orbit interaction, consequently termed ``improper.''...
The orbital magnetic moment is still surprisingly not well understood, in contrast to the spin part. Its description finite systems, such as isolated atoms and molecules, problematic, but it was only recently that a rigorous picture provided for extended systems. Here we focus on an intermediate class of systems: adatoms placed non-magnetic surface. We show essential quantity ground-state charge current density, presence spin-orbit coupling, set out its first-principles description. This...
Interfacing magnetism with superconductivity gives rise to a wonderful playground for intertwining key degrees of freedom: Cooper pairs, spin, charge, and spin-orbit interaction, from which emerge wealth exciting phenomena, fundamental in the nascent field superconducting spinorbitronics topological quantum technologies. Magnetic exchange interactions (MEI), being isotropic or chiral such as Dzyaloshinskii-Moriya (DMI), are vital establishing magnetic behavior at these interfaces well...
We present a first-principles study of the surface magnetism induced by Cr, Mn, Fe and Co adatoms on (111) surfaces Rh, Pd, Ag, Ir, Pt Au. first describe how different contributions to enter magnetic stray field, with special attention paid orbital moments. Then we results for spin moments adatoms, moments, latter being further divided into atomic inter-atomic contributions. investigate is determined chemical nature elements involved, such as filling d-orbitals properties itinerant electrons...