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Levitated nano-ferromagnet confirms a 160-year-old physical prediction

Ferromagnets, such as iron, cobalt, and nickel, are materials with a strong, spontaneous, and permanent magnetic field. Over 150 years ago, the physicist and mathematician James Clerk Maxwell speculated that under specific conditions, non-spinning ferromagnets or electromagnets would behave as gyroscopes, objects that maintain their orientation, typically due to the angular momentum arising from spinning.

Maxwell hypothesized that this unique gyroscopic behavior would arise from the relationship between a ferromagnet’s magnetism and its angular momentum within a specific set-up. While numerous studies tested this prediction, so far it had never been proven experimentally.

Researchers at the Institute of Photonics and Nanotechnology IFN-CNR and the Bruno Kessler Foundation recently observed the effect predicted by Maxwell in a non-spinning and levitated ferromagnetic sphere. Their observations, presented in a paper published in Physical Review Letters, could open new exciting possibilities for the development of quantum technologies and for the collection of highly precise measurements.

Tiny flexible lasers enable force sensing inside living cells

Researchers have developed tiny flexible lasers that can be used to measure forces inside living cells. The new lasers could help illuminate various biological processes, including those involved in early development and tumor progression.

“Biological forces inside and between cells play an important role in many diseases,” said research team leader Marcel Schubert from the University of Cologne. “For example, when cancer cells invade tissue, they have to squeeze through the other cells. Our tiny lasers make it possible to measure forces on the scale of individual cells, which has previously been very difficult to accomplish.”

In the journal Optical Materials Express, the researchers describe their new spherical whispering gallery mode microbead lasers, which measure just 20 microns, about the width of a human hair. Whispering gallery mode lasers trap light in circular paths—in this case, inside a tiny elastomer bead doped with fluorescent dye—where the light circulates and amplifies until it emits coherent laser light.

Spintronics at BESSY II: Real-time analysis of magnetic bilayer systems

Spintronic devices enable data processing with significantly lower energy consumption. They are based on the interaction between ferromagnetic and antiferromagnetic layers. Now, a team from Freie Universität Berlin, HZB and Uppsala University has succeeded in tracking—separately for each layer—how the magnetic order changes after a short laser pulse has excited the system. The researchers were also able to identify the main cause of the loss of antiferromagnetic order in the oxide layer: The excitation is transported from the hot electrons in the ferromagnetic metal to the spins in the antiferromagnet. The findings are published in the journal Physical Review Letters.

While conventional microelectronics involves the movement of electric charges, spintronics is based on electron spins. Manipulating spins requires less energy than transporting charged particles. Consequently, spintronic components offer the potential for significant energy savings and high processing speeds.

However, future applications will require clock speeds in the terahertz range, which are not yet achievable today. The clock speeds of current spin-based applications are up to a hundred times lower. In order to advance spintronics, a large team at the Transregio Collaborative Research Center CRC/TRR 227 is investigating spin dynamics in solids at atomic resolution and on ultrafast timescales.

Microscopic sensors uncover how liquids turn glassy without structural change

A scientific discovery by researchers at Tel Aviv University’s School of Chemistry offers a new perspective on a long-standing scientific mystery: how does a flowing liquid suddenly become a rigid, almost frozen material, without changing its structure? This phenomenon, known as the “glass transition,” has puzzled physicists for over a hundred years. The study proposes a new experimental approach to observing this elusive process—by tracking the motion of tiny particles that serve as microscopic “sensors” within the material.

The study was conducted by Prof. Haim Diamant and Prof. Yael Roichman of the School of Chemistry at Tel Aviv University, together with the research group of Prof. Stefan Egelhaaf at Heinrich Heine University Düsseldorf. The findings were published in the journal Nature Physics.

Light-responsive hydrogels enable fast and precise control of soft materials

Researchers at Tampere University have recently demonstrated that light can be used to precisely reshape soft materials without mechanical contact. They have developed light-responsive hydrogel thin films that enable programmable surfaces with high sensitivity, rapid response, precise spatial control and reversibility. The technology opens new possibilities for tunable devices in photonics, sensing and biomedicine.

Until now, responses in hydrogel films have typically been limited to timescales of tens of seconds and spatial resolutions of tens of micrometers—about the thickness of a fine human hair—restricting practical applications. In contrast, the university’s Smart Photonic Materials research group has achieved control on sub-second timescales and sub-micron resolution, marking a significant advance in speed and precision. The findings are published in the journal Nature Communications.

Light-responsive hydrogels are particularly attractive for mimicking dynamic microstructures found in nature. The materials absorb and release water when exposed to light, enabling accurate and remote actuation in lightweight structures. Such properties are well suited for applications including soft micro-robots, remote drug delivery systems and active cell culture platforms.

Observing exotic quasiparticle states in kagome superconductor CsV₃Sb₅

A research team led by Prof. Hao Ning of the Hefei Institutes of Physical Science of the Chinese Academy of Sciences, in collaboration with Anhui University and the University of Science and Technology of China, has identified two distinct types of unusual low-energy quasiparticle states in the kagome superconductor CsV3Sb5 using single-atom impurities as local “quantum probes” combined with scanning tunneling spectroscopy.

The study was recently published in Nature Physics.

CsV3Sb5 has attracted growing interest for its unusual crystal structure and complex quantum phenomena. Evidence for time-reversal symmetry breaking remains under debate, and the mechanism of its superconductivity is still not fully understood. Studying its response to single-atom impurities provides a promising way to address these questions.

Scientists Just Discovered Light Can Actually Slow Plant Growth

Light doesn’t just help plants grow, it also strengthens their internal structure by tightening the connection between tissues. This added rigidity can actually slow growth, revealing a hidden balance between strength and expansion.

Light is widely recognized as a key factor in plant growth, but scientists are still uncovering the details of how it works. Researchers at Osaka Metropolitan University have now identified a previously unknown process that helps explain how light influences plant development.

Light increases adhesion between plant tissues.

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