Phys.org December 19, 2024 When the skyrmion lattice (SkL) acquires a drift velocity under conduction electron flow, an emergent electric field is also generated. The resulting emergent electrodynamics dictate the magnitude of the topological Hall effect (THE) by the relative motion of SkL and conduction electrons. Researchers in Japan reported the emergent electrodynamics induced by SkL motion in Gd2PdSi3, facilitated by its giant THE. They observed the dynamic transition of the SkL motion from the pinned to creep regime and finally to the flow regime, in which the THE was totally suppressed. According to the researchers the Galilean relativity required […]
Category Archives: Skyrmions
Controlling skyrmions at room-temperature in 2D topological spin structure technology
Phys. org November 6, 2024 Room-temperature ferromagnetism in 2D van der Waals (vdW) materials, such as Fe3GaTe2 (FGaT), has garnered significant interest as a robust platform for 2D spintronic applications. Although many fundamental operations essential for the realization of 2D spintronics devices are experimentally confirmed using these materials at room temperature, the potential applications of magnetic skyrmions in FGaT systems at room temperature remain unexplored. An international team of researchers (Republic of Korea, USA – Lawrence Berkeley National Laboratory) showed the current-induced generation of magnetic skyrmions in FGaT flakes employing high-resolution magnetic transmission soft X-ray microscopy using a mechanism based […]
Heat used to transform antiskyrmions to skyrmions and back
Riken Research June 19, 2024 Recent studies have experimentally discovered several host materials for antiskyrmions have been identified, but their control via thermal current remains elusive. An international team of researchers (Japan, Germany) used thermal current to drive the transformation between skyrmions, antiskyrmions and non-topological bubbles, as well as the switching of helical states in the antiskyrmion-hosting ferromagnet (Fe0.63Ni0.3Pd0.07)3P at room temperature. They discovered that a temperature gradient drove a transformation from antiskyrmions to non-topological bubbles to skyrmions while under a magnetic field and observed the opposite, unidirectional transformation from skyrmions to antiskyrmions at zero-field, suggesting that the antiskyrmion, more […]
Dynamics of skyrmion spin states confirmed in neutron-scattering experiments
Phys.org. November 11, 2023 Some magnetic systems feature spin textures, real-space patterns in the orientation of spins that can topologically form non-trivial configurations. Among them, a vortex-like spin swirling texture known as a magnetic skyrmion has attracted particular attention. Lattices of skyrmions form in the helimagnet MnSi with a periodicity of 18 nm, which makes them amenable to investigation by Lorentz transmission electron microscopy in real space and by small-angle neutron scattering in momentum space. An international team of researchers (Japan, France, Sweden, Czech Republic) examined the low-energy excitations of the skyrmion state in MnSi by using the neutron spin-echo technique […]
Imaging the elusive skyrmion: Neutron tomography reveals their shapes and dynamics in bulk materials
Phys.org September 26, 2023 Commonly observed in thin systems as two-dimensional sheets, in three dimensions skyrmions form tubes that are thought to nucleate and annihilate along their depth on points of vanishing magnetization. However, a lack of techniques that can probe the bulk of the material has made it difficult to perform experimental visualizations of skyrmion lattices and their stabilization through defects. An international team of researchers ( Canada, USA – NIST, SUNY Buffalo, Germany) provided three-dimensional visualizations of a bulk Co8Zn8Mn4 skyrmion lattice through a tomographic algorithm applied to multiprojection small-angle neutron scattering measurements. Reconstructions of the sample showed […]
Generating biskyrmions in a rare earth magnet
Phys.org September 16, 2023 The low stability of most magnetic skyrmions leads to either a narrow temperature range in which they can exist, a low density of skyrmions, or the need for an external magnetic field, which greatly limits their wide application. An international team of researchers (USA – NIST, Japan, South Korea) has reported real-space imaging of a two-dimensional skyrmion lattice in a thin film of Fe0.5Co0.5Si using Lorentz transmission electron microscopy. With a magnetic field of 50–70 mT applied normal to the film, they observed skyrmions in the form of a hexagonal arrangement of swirling spin textures, with a […]
The transformation between different topological spin textures
Phys.org November 11, 2022 Skyrmions and bimerons are versatile topological spin textures that can be used as information bits for both classical and quantum computing. An international team of researchers (Japan, China, Australia) has demonstrated the creation of isolated skyrmions and their subsequent transformation to bimerons by harnessing the electric current-induced Oersted field and temperature-induced perpendicular magnetic anisotropy variation. The reversible transformation between skyrmions and bimerons was controlled by the current amplitude and scanning direction. Both skyrmions and bimerons could be created in the same system through the skyrmion-bimeron transformation and magnetization switching. Deformed skyrmion bubbles and chiral labyrinth domains […]
Magnetic skyrmions: Two methods for creating them and guiding their motion
Phys.org September 7, 2022 Magnetic skyrmions are envisioned as information carriers in future information technology. Skyrmions in thin magnetic films may act as an ideal test bed to study the dynamics of topologically non-trivial magnetic quasi-particles. To study the skyrmions reliable generation of the magnetic skyrmion at controlled positions is required. An international team of researchers (Germany, the Netherlands) developed full nanometer-scale control of the skyrmion generation by two independent approaches employing He+-ion irradiation or using backside reflective masks. The influence of nanopatterned backside aluminum masks on the optical excitation was studied in two sample geometries with varying layer sequence […]
Unlocking the recipe for designer magnetic particles for next generation computing technologies
Phys.org August 4, 2022 Recently ensembles of chiral spin textures, consisting of skyrmions and magnetic stripes, are shown to possess rich interactions with potential for device applications. However, several fundamental aspects of chiral spin texture phenomenology remain to be elucidated, including their domain wall (DW) structure, thermodynamic stability, and morphological transitions. An international team of researchers (Singapore, USA – Lawrence Berkeley National Laboratory) has shown the evolution of these textural characteristics unveiled on a tunable multilayer platform using a combination of full-field electron and soft X-ray microscopies with numerical simulations. They demonstrated the increasing chiral interactions, the emergence of Néel […]
Researchers create exotic magnetic structures with laser light
Phys.org April 25, 2022 To interface skyrmionics with electronic devices requires efficient and reliable ways of creating and destroying such excitations. An international team of researchers (Germany, USA – Flatiron Institute, Sweden) unravel the microscopic mechanism behind ultrafast skyrmion generation by femtosecond laser pulses in transition metal thin films. They employed a theoretical approach based on a two-band electronic model and showed that by exciting the itinerant electronic subsystem with a femtosecond laser ultrafast skyrmion nucleation can occur on a 100 fs timescale. By combining numerical simulations with an analytical treatment, they identified the coupling between electronic currents and the […]