Phys.org September 11, 2023 Magnetic skyrmions have garnered considerable interest due to a variety of electromagnetic responses that are governed by the topology. The topology that creates a microscopic gyro tropic force also causes detrimental effects, such as the skyrmion Hall effect, which is a well-studied phenomenon highlighting the influence of topology on the deterministic dynamics and drift motion. Furthermore, the gyrotropic force is anticipated to have a substantial impact on stochastic diffusive motion; however, the predicted repercussions have yet to be demonstrated, even qualitatively. An international team of researchers (Germany, Japan, Sweden, Czech Republic) demonstrated enhanced thermally activated diffusive […]
Tag Archives: Skyrmions
Study shows that skyrmions and antiskyrmions can coexist at different temperatures
Phys.org July 21, 2022 A fundamental property of particles and antiparticles is their ability to annihilate one another. A similar behaviour is predicted for magnetic solitons1—localized spin textures that can be distinguished by their topological index Q. Theoretically, magnetic topological solitons with opposite values of Q, such as skyrmions and antiskyrmions, are expected to be able to continuously merge and annihilate. An international team of researchers (Germany, Sweden) demonstrated the creation and annihilation of skyrmion–antiskyrmion pairs in an exceptionally thin film of the cubic chiral magnet of B20-type FeGe. According to the researchers their observations are highly reproducible and are […]
Researchers use tiny magnetic swirls to generate true random numbers
Science Daily February 7, 2022 Researchers at Brown University have shown that the local dynamics of skyrmions, in contrast to the global dynamics of a skyrmion, can be introduced to provide effective functionalities for versatile computing. A single skyrmion interacting with local pinning centres under thermal effects can fluctuate in time and switch between a small-skyrmion and a large-skyrmion state, thereby serving as a robust true random number generator for probabilistic computing. Moreover, neighbouring skyrmions exhibit an anti-correlated coupling in their fluctuation dynamics. Both the switching probability and the dynamic coupling strength can be tuned by modifying the applied magnetic […]
New Exotic Magnetic Quasiparticle: “Skyrmion Bundle” Joins Topological Zoo
SciTech Daily August 23, 2021 Although theory has proposed “skyrmion bags” and “high-order skyrmions” as multi-Q topological magnetic structures, their experimental observations remain elusive. Using 3D micromagnetic simulation approach, an international team of researchers (China, USA – University of New Hampshire) proposed a new 3D multi-Q topological structure, skyrmion bundle. Through experimental verification they found collective motions and topological sign dependence of Hall sideway shifts of skyrmion bundles driven by nanosecond pulsed currents. Skyrmion bundles can serve as information carriers applied in distinct spintronic devices such as multi-state memory and information interconnect and should pave a new field of topological […]
Exotic property of ‘ambidextrous’ crystals points to new magnetic phenomena
Phys.org August 4, 2021 Researchers in Sweden used symmetry-based analysis and numerical computations to predict the existence of antichiral ferromagnetism—a kind of ferromagnetic ordering when both types of chirality (handedness) exist simultaneously and alternate in space. They predicted a fundamentally different magnetic ordering in tetrahedral ferromagnets. They showed that antichiral ferromagnetism can be observed in a class of crystals in which many minerals are formed naturally by studying magnetic ordering in the structure with tetrahedral crystal symmetry and used micromagnetic analysis to derive the new antichiral ordering. The proposed magnetic ordering might result in a rich family of magnetic phenomena […]
Magnetic whirls in confined spaces
Nanowerk March 4, 2021 An international team of researchers (Germany, China) experimentally probed the dramatic influence of confinement on diffusion and study the skyrmion diffusion in confined geometries varying both the symmetry of the elements and the number of skyrmions within the element, studying the evolution from a sparse population to a fully lattice‐like situation and skyrmion population. In the triangular geometry, they found that the dynamics varies drastically for numbers of skyrmions that can form a regular order, thus being commensurate with the geometry, as compared to numbers of skyrmions that are incommensurate with the geometry. The findings confirm experimentally […]
New shortcut enables faster creation of spin pattern in magnet
Nanowerk October 5, 2020 The fast creation of topological phases in matter requires massive reorientation of charge or spin degrees of freedom. An international team of researchers (Germany, Belgium, USA – MIT, Italy, the Netherlands) report the picosecond emergence of an extended topological phase that comprises many magnetic skyrmions. The nucleation of this phase, followed in real time via single-shot soft X-ray scattering after infrared laser excitation, is mediated by a transient topological fluctuation state. This state is enabled by the presence of a time-reversal symmetry-breaking perpendicular magnetic field and exists for less than 300 ps. Atomistic simulations indicate that the […]
Study reveals magnetic process that can lead to more energy-efficient memory in computers
Science Daily June 30, 2020 Magnetic memory and logic devices that use skyrmions rely on current-controlled motion of skyrmions. A team of researchers in the US (Virginia Commonwealth University, UCLA) has shown that using skyrmions that are fixed in space could lead to more compact and energy-efficient devices. They manipulated fixed magnetic skyrmions using voltage-controlled magnetic anisotropy to show that skyrmions can be stabilized in antiferromagnet/ferromagnet/oxide heterostructure films without any external magnetic field due to an exchange bias field. The isolated skyrmions are annihilated or formed by applying voltage pulses and skyrmions can be created from chiral domains by increasing […]
Researchers generate optical skyrmions
Phys.org July 27, 2018 An international team of researchers (Israel, Albania) generated skyrmions using the electrical field of electromagnetic waves. They demonstrated that in contrast to “regular” light waves, whose electrical fields usually point along a specific direction an electric field can take on a “skyrmion” shape and simultaneously face in all directions and they are robust against various defects in the material hosting the electromagnetic waves. The discovery could enable future replication of this effect in a wide range of systems and materials, including liquids, nanoparticle systems and even cold atomic gasses. It might also lay the ground for […]