August 2023

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. 

Researchers from the Technion – Israel Institute of Technology, Tel Aviv University and China's Shanghai Jiao Tong University have developed a coherent and controllable spin-optical laser based on a single atomic layer. This was enabled by coherent spin-dependent interactions between a single atomic layer and a laterally confined photonic spin lattice, the latter of which supports high-Q spin-valley states through the photonic Rashba-type spin splitting of a bound state in the continuum.

The team's achievement could pave the way towards studying coherent spin-dependent phenomena in both classical and quantum regimes, opening new horizons in fundamental research and optoelectronic devices exploiting both electron and photon spins.

Researchers from MIT and Tohoku University have reported a representative effect of the anomalous dynamics at play when an electric current is applied to a class of magnetic materials called non-collinear antiferromagnets. 

Non-collinear antiferromagnets have properties distinct from conventional magnetic materials—in traditional collinear magnets, the magnetic moments align in a collinear fashion. However, in non-collinear ones, the moments form finite angles between one another. Scientists describe these non-collinear arrangements as a single order parameter, the octupole moment, which has been demonstrated to be critical for determining the exotic properties of the materials.

Researchers from MIT, Princeton University and Politecnico di Milano have found a way to tune the spin density in diamonds by applying an external laser or microwave beam. These findings could open new possibilities for advanced quantum devices.

Spin defects make crystalline materials highly useful for quantum-based devices such as ultrasensitive quantum sensors, quantum memory devices, or systems for simulating the physics of quantum effects. Varying the spin density in semiconductors can lead to new properties in a material, but this density is usually fleeting and elusive, thus hard to measure and control locally. Now, the team of researchers has found a way to tune the spin density in diamonds, changing it by a factor of two, by applying an external laser or microwave beam. 

A team of researchers from the DOE/Argonne National Laboratory and U.S. additional laboratories and universities have reported a mechanical response across a layered magnetic material tied to changing its electron spin. This response could have important applications in nanodevices requiring ultra-precise and fast motion control.

A little over a century ago, physicists Albert Einstein and Wander de Haas reported a surprising effect in ferromagnets: if you suspend an iron cylinder from a wire and expose it to a magnetic field, it will start rotating if you simply reverse the direction of the magnetic field. "Einstein and de Haas's experiment is almost like a magic show," said Haidan Wen, a physicist in the Materials Science and X-ray Science divisions of the U.S. Department of Energy's (DOE) Argonne National Laboratory. ​"You can cause a cylinder to rotate without ever touching it."