429 results match your criteria: "and Institute for Advanced Simulation[Affiliation]"

Magneto-responsiveness in living organisms, exemplified by migratory birds navigating vast distances, offers inspiration for soft robots and human-computer interfaces. However, achieving both high magneto-responsiveness and resilient mechanical properties in synthetic materials has been challenging. Here, we develop magneto-iono-elastomers (MINEs), combining exceptional magnetization [2.

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The adsorption of ellipsoidal colloidal particles on liquid interfaces induces interfacial deformation, resulting in anisotropic interface-mediated interactions and the formation of superstructures. Soft prolate-shaped microgels at the air-water interface offer an ideal model for studying spontaneous capillary-driven self-assembly due to their tunable aspect ratio, controlled functionality, and softness. These microgels consist of a polystyrene core surrounded by a cross-linked, fluorescently labeled poly([Formula: see text]-isopropylmethylacrylamide) shell.

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Low efficiency of Janus microswimmers as hydrodynamic mixers.

Phys Rev E

October 2024

Laboratory for Soft Materials and Interfaces, Department of Materials, ETH Zürich, Vladimir-Prelog-Weg 5, 8093 Zürich, Switzerland.

The generation of fluid flows by autophoretic microswimmers has been proposed as a mechanism to enhance mass transport and mixing at the micro- and nanoscale. Here, we experimentally investigate the ability of model 2D active baths of photocatalytic silica-titania Janus microspheres to enhance the diffusivity of tracer particles at different microswimmer densities below the onset of collective behavior. Inspired by the similarities between our experimental findings and previous results for biological microorganisms, we then model our Janus microswimmers using a general squirmer framework, specifically treating them as neutral squirmers.

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Spin Spiral State at a Ferromagnetic Gd Vacuum Interface.

Phys Rev Lett

November 2024

Physikalisches Institut, Experimentelle Physik II, Universität Würzburg, Am Hubland, 97074 Würzburg, Germany.

Centrosymmetric bulk magnets made of layered Gd intermetallics had been discovered recently to exhibit helical spin spirals with a wavelength of ≈2  nm that transform into skyrmion lattices at certain magnetic fields. Here we report on the observation of a spin spiral state at the Gd(0001) surface. Spin-polarized scanning tunneling microscopy images show striped regions with a periodicity of about 2 nm.

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Spurious self-feedback of mean-field predictions inflates infection curves.

Phys Rev E

August 2024

Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA-Institute Brain Structure-Function Relationships (INM-10), Jülich Research Centre, 52428 Jülich, Germany.

The susceptible-infected-recovered (SIR) model and its variants form the foundation of our understanding of the spread of diseases. Here, each agent can be in one of three states (susceptible, infected, or recovered), and transitions between these states follow a stochastic process. The probability of an agent becoming infected depends on the number of its infected neighbors, hence all agents are correlated.

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We present a detailed analysis of the electronic properties of graphene/Eu/Ni(111). By using angle- and spin-resolved photoemission spectroscopy and ab initio calculations, we show that the intercalation of Eu in the graphene/Ni(111) interface gives rise to a gapped freestanding dispersion of the ππ^{*} Dirac cones at the K[over ¯] point with an additional lifting of the spin degeneracy due to the mixing of graphene and Eu states. The interaction with the magnetic substrate results in a large spin-dependent gap in the Dirac cones with a topological nature characterized by a large Berry curvature and a spin-polarized Van Hove singularity, whose closeness to the Fermi level gives rise to a polaronic band.

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The exchange bias phenomenon, inherent in exchange-coupled ferromagnetic and antiferromagnetic systems, has intrigued researchers for decades. Van der Waals materials, with their layered structures, offer an ideal platform for exploring exchange bias. However, effectively manipulating exchange bias in van der Waals heterostructures remains challenging.

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Article Synopsis
  • Epitaxial graphene/ferromagnetic metal heterostructures are promising for spintronic devices due to their unique magnetic properties and stability.
  • The research focuses on understanding the spin-orbit coupling at the interface of graphene and cobalt on iridium, revealing that hybridization contributes to strong coupling effects.
  • Findings indicate that while thin cobalt layers exhibit significant spin-orbit effects, these vanish with thicker layers, highlighting the importance of graphene's electronic interactions for future spintronic applications.
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Magnetic skyrmions are quasi-particles with a swirling spin texture that form two-dimensional lattices. Skyrmion lattices can exhibit defects in response to geometric constraints, variations of temperature or applied magnetic fields. Measuring deformations in skyrmion lattices is important to understand the interplay between the lattice structure and external influences.

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Observation of Long-Range Current-Induced Torque in Ni/Pt Bilayers.

Nano Lett

June 2024

Department of Applied Physics and Physico-Informatics, Keio University, Yokohama 223-8522, Japan.

The generation of current-induced torques through the spin Hall effect in Pt has been key to the development of spintronics. In prototypical ferromagnetic-metal/Pt devices, the characteristic length of the torque generation is known to be about 1 nm due to the short spin diffusion length of Pt. Here, we report the observation of a long-range current-induced torque in Ni/Pt bilayers.

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Two ultimately thin vanadium-rich 2D materials based on VS are created via molecular beam epitaxy and investigated using scanning tunneling microscopy, X-ray photoemission spectroscopy, and density functional theory (DFT) calculations. The controlled synthesis of stoichiometric single-layer VS or either of the two vanadium-rich materials is achieved by varying the sample coverage and sulfur pressure during annealing. Through annealing of small stoichiometric single-layer VS islands without S pressure, S-vacancies spontaneously order in 1D arrays, giving rise to patterned adsorption.

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Bacteria in biofilms form complex structures and can collectively migrate within mobile aggregates, which is referred to as swarming. This behavior is influenced by a combination of various factors, including morphological characteristics and propulsive forces of swimmers, their volume fraction within a confined environment, and hydrodynamic and steric interactions between them. In our study, we employ the squirmer model for microswimmers and the dissipative particle dynamics method for fluid modeling to investigate the collective motion of swimmers in thin films.

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Article Synopsis
  • Magnetic skyrmions are special tiny magnetic shapes that can move around and interact like little particles when pushed by external forces.
  • Scientists are studying these skyrmions to make new technology like faster memory and advanced computer systems.
  • In this experiment, researchers were able to see different types of skyrmions in special materials at room temperature and learned how their stability and movement are affected by different factors.
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Article Synopsis
  • The Modular-Integrative Modeling approach is a new framework in neuroscience designed to create brain models that accurately reflect biological processes.
  • It aims to combine realistic biological elements with functional performance, offering a comprehensive understanding of how the brain interacts with the body and environment.
  • This perspective emphasizes the importance of integrating different aspects of brain function for a better overall view of neuroscience.
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Biological and artificial microswimmers often have to propel through a variety of environments, ranging from heterogeneous suspending media to strong geometrical confinement. Under confinement, local flow fields generated by microswimmers, and steric and hydrodynamic interactions with their environment determine the locomotion. We propose a squirmer-like model to describe the motion of microswimmers in cylindrical microchannels, where propulsion is generated by a fixed surface slip velocity.

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Article Synopsis
  • * Magnetic exchange interactions (MEIs) play a critical role in determining the magnetic behavior at these interfaces, affecting transport phenomena and the existence of topological objects.
  • * A proposed methodology allows for the extraction of MEI from electronic structure simulations, showing changes in magnetic order and chirality when tuning the superconducting order parameter in a Mn layer on a Nb(110) surface.
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Crystal Thermal Transport in Altermagnetic RuO_{2}.

Phys Rev Lett

February 2024

Centre for Quantum Physics, Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement (MOE), School of Physics, Beijing Institute of Technology, Beijing 100081, China.

We demonstrate the emergence of a pronounced thermal transport in the recently discovered class of magnetic materials-altermagnets. From symmetry arguments and first-principles calculations performed for the showcase altermagnet, RuO_{2}, we uncover that crystal Nernst and crystal thermal Hall effects in this material are very large and strongly anisotropic with respect to the Néel vector. We find the large crystal thermal transport to originate from three sources of Berry's curvature in momentum space: the Weyl fermions due to crossings between well-separated bands, the strong spin-flip pseudonodal surfaces, and the weak spin-flip ladder transitions, defined by transitions among very weakly spin-split states of similar dispersion crossing the Fermi surface.

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Electrostatic gating has emerged as a powerful technique for tailoring the magnetic properties of two-dimensional (2D) magnets, offering exciting prospects including enhancement of magnetic anisotropy, boosting Curie temperature, and strengthening exchange coupling effects. Here, we focus on electrical control of the ferromagnetic resonance of the quasi-2D Kagome magnet Cu(1,3-bdc). By harnessing an electrostatic field through ionic liquid gating, significant shifts are observed in the ferromagnetic resonance field in both out-of-plane and in-plane measurements.

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A modular and adaptable analysis pipeline to compare slow cerebral rhythms across heterogeneous datasets.

Cell Rep Methods

January 2024

Institute of Neuroscience and Medicine (INM-6) and Institute for Advanced Simulation (IAS-6) and JARA-Institute Brain Structure-Function Relationships (INM-10), Jülich Research Centre, Jülich, Germany.

Neuroscience is moving toward a more integrative discipline where understanding brain function requires consolidating the accumulated evidence seen across experiments, species, and measurement techniques. A remaining challenge on that path is integrating such heterogeneous data into analysis workflows such that consistent and comparable conclusions can be distilled as an experimental basis for models and theories. Here, we propose a solution in the context of slow-wave activity (<1 Hz), which occurs during unconscious brain states like sleep and general anesthesia and is observed across diverse experimental approaches.

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Enantioselective Adsorption on Magnetic Surfaces.

Adv Mater

April 2024

Peter Grünberg Institute, Electronic Properties (PGI-6), Forschungszentrum Jülich, 52425, Jülich, Germany.

From the beginning of molecular theory, the interplay of chirality and magnetism has intrigued scientists. There is still the question if enantiospecific adsorption of chiral molecules occurs on magnetic surfaces. Enantiomer discrimination was conjectured to arise from chirality-induced spin separation within the molecules and exchange interaction with the substrate's magnetization.

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The proximity effect at a highly transparent interface of an -wave superconductor (S) and a topological insulator (TI) provides a promising platform to create Majorana zero modes in artificially designed heterostructures. However, structural and chemical issues pertinent to such interfaces have been poorly explored so far. Here, we report the discovery of Pd diffusion-induced polarization at interfaces between superconductive Pd(BiTe) (PBT, 0 ≤ ≤ 1) and Pd-intercalated BiTe by using atomic-resolution scanning transmission electron microscopy.

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Characterizing the connectomic and morphological diversity of thalamic neurons is key for better understanding how the thalamus relays sensory inputs to the cortex. The recent public release of complete single-neuron morphological reconstructions enables the analysis of previously inaccessible connectivity patterns from individual neurons. Here we focus on the Ventral Posteromedial (VPM) nucleus and characterize the full diversity of 257 VPM neurons, obtained by combining data from the MouseLight and Braintell projects.

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The emergence of large-scale order in self-organized systems relies on local interactions between individual components. During bacterial cell division, FtsZ-a prokaryotic homologue of the eukaryotic protein tubulin-polymerizes into treadmilling filaments that further organize into a cytoskeletal ring. In vitro, FtsZ filaments can form dynamic chiral assemblies.

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The phase of the quantum-mechanical wave function can encode a topological structure with wide-ranging physical consequences, such as anomalous transport effects and the existence of edge states robust against perturbations. While this has been exhaustively demonstrated for electrons, properties associated with the elementary quasiparticles in magnetic materials are still underexplored. Here, we show theoretically and via inelastic neutron scattering experiments that the bulk ferromagnet MnGe hosts gapped topological Dirac magnons.

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