Research / Technical

Researchers from Beijing University of Technology, South China University of Technology, Forschungszentrum Jülich and Uppsala University have reported the first experimental evidence of hopfions, which are magnetic spin structures predicted decades ago that have become a fascinating research topic in recent years.

The team used transmission electron microscopy to observe hopfions forming coupled states with skyrmion strings in B20-type FeGe plates. They provided a protocol for nucleating such hopfion rings, which they verified using Lorentz imaging and electron holography. The scientists' results are said to be highly reproducible and in full agreement with micromagnetic simulations. 

Researchers from Japan's RIKEN Center for Emergent Matter Science (CEMS) and Ochanomizu University, UK's  University of Birmingham, Sweden's Lund University, Canada's Université de Sherbrooke, Czech Republic's Nuclear Physics Institute, France's Institut Max von Laue-Paul Langevin (ILL) have advanced low-energy devices based on spintronics, by measuring the dynamics of tiny magnetic vortices.

The team examined the low-energy excitations of the skyrmion state in MnSi by using the neutron spin-echo technique under small-angle neutron scattering conditions. The scientists observed an asymmetric dispersion of the phason excitations of the lattice because of the string-like structure of the skyrmion cores.

Researchers from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), led by Associate Prof. Li Xingxing and Prof. Yang Jinlong, recently developed a novel chemical method for two-dimensional metal-organic lattices.

In spintronics, it is paramount to develop an efficient way to reversibly control the spin order of materials. Though various physical methods have been proposed, chemically achieving this has posed significant challenges. The researchers proposed the utilization of the well-recognized lactim−lactam tautomerization process to reversibly modulate the magnetic phase transition in two-dimensional (2D) organometallic lattices. This could offer new pathways for controlling the electrical and magnetic characteristics of materials.

Researchers from The Ohio State University in the U.S, Uppsala University in Sweden and the UK's University of Exeter have used a novel technique to confirm a previously undetected physics phenomenon that could be used to improve data storage in the next generation of computer devices.

Spintronic memories, like those used in some high-tech computers and satellites, use magnetic states generated by an electron's intrinsic angular momentum to store and read information. Depending on its physical motion, an electron's spin produces a magnetic current. Known as the "spin Hall effect," this has key applications for magnetic materials across many different fields, ranging from low power electronics to fundamental quantum mechanics.

Researchers from Tohoku University, Chinese Academy of Sciences (CAS), Guangxi Normal University, Kyushu University and Japan Atomic Energy Agency have reported a significant breakthrough which could revolutionize next-generation electronics by enabling non-volatility, large-scale integration, low power consumption, high speed, and high reliability in spintronic devices.

Spintronic devices, such as magnetic random access memory (MRAM), utilize the magnetization direction of ferromagnetic materials for information storage and rely on spin current, a flow of spin angular momentum, for reading and writing data. Conventional semiconductor electronics have faced limitations in achieving these qualities. However, the emergence of three-terminal spintronic devices, which employ separate current paths for writing and reading information, presents a solution with reduced writing errors and increased writing speed. Nevertheless, the challenge of reducing energy consumption during information writing, specifically magnetization switching, remains a critical concern.

Researchers at Johannes Gutenberg University Mainz, the University of Konstanz and Tohoku University in Japan have increased the diffusion of magnetic whirls, so called skyrmions, by a factor of ten.

Science often does not simply consider the spin of an individual electron, but rather magnetic whirls composed of numerous spins. These whirls, called skyrmions, emerge in magnetic metallic thin layers and can be considered as two-dimensional quasi-particles. On the one hand, the whirls can be deliberately moved by applying a small electric current to the thin layers; on the other hand, they move randomly and extremely efficiently due to diffusion. The feasibility of creating a functional computer based on skyrmions was demonstrated by a team of researchers from Johannes Gutenberg University Mainz (JGU), led by Professor Dr. Mathias Kläui, using an initial prototype. This prototype consisted of thin, stacked metallic layers, some only a few atomic layers thick.

A new study at BESSY II analyzes the formation of skyrmions in ferrimagnetic thin films of dysprosium and cobalt in real time and with high spatial resolution. This could be an important step towards characterizing suitable materials with skyrmions more precisely. 

Magnetic skyrmions are tiny vortices-like of magnetic spin textures that can, in principle, be used for spintronic devices. But currently it is still difficult to control and manipulate skyrmions at room temperature.

Researchers from Monash University in Australia have shown in their recent theoretical study that ‘trimming’ the edge-states of a topological insulator can yield a new class of materials featuring unconventional ‘two way’ edge transport.

The new material, a topological crystalline insulator (TCI) forms a promising addition to the family of topological materials and broadens the scope of materials with topologically nontrivial properties. Its distinctive reliance on symmetry also paves the way for novel techniques to manipulate edge transport, offering potential applications in future transistor devices. For example, ‘switching’ the TCI via an electric field that breaks the symmetry supporting the nontrivial band topology, thus suppressing the edge current.

Researchers at the University of Cambridge,  University of Manchester, University of Oxford,  Swansea University, Jilin University, University of Namur, University of Mons, Donostia International Physics Centre, University of Würzburg have developed a way to control the interaction of light and quantum 'spin' in organic semiconductors, that even works at room temperature.

The international team of researchers has found a way to use particles of light as a 'switch' that can connect and control the spin of electrons, making them behave like tiny magnets that could be used for quantum applications. The researchers designed modular molecular units connected by tiny 'bridges'. Shining a light on these bridges allowed electrons on opposite ends of the structure to connect to each other by aligning their spin states. Even after the bridge was removed, the electrons stayed connected through their aligned spins.

Researchers from Korea's Institute for Basic Science (IBS), China's National University of Defense Technology and Harvard University in the U.S have made a fascinating breakthrough that can potentially harness fluctuations in semiconductors caused by Random Telegraph Noise (RTN), a type of unwanted electronic noise that has long been a nuisance in electronic systems.

Led by Professor Lee Young Hee from IBS, the team reported that magnetic fluctuations and their gigantic RTN signals can be generated in a vdW-layered semiconductor by introducing vanadium in tungsten diselenide (V-WSe₂) as a minute magnetic dopant.