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For many years, physics studies focused on two main types of magnetism, namely ferromagnetism and antiferromagnetism. The first type entails the alignment of electron spins in the same direction, while the latter entails the alignment of electron spins in alternating, opposite directions.

Yet recent studies have discovered a new kind of magnetism, referred to as altermagnetism, which does not fit into either of the previously identified categories. Altermagnetism is characterized by the breaking of time-reversal symmetry (i.e., the symmetry of physical laws when time is reversed) and spin-split band structures, in materials that retain a zero net magnetization.

Researchers at the Chinese Academy of Sciences and other institutes in China recently uncovered a new material that exhibits altermagnetism at room temperature, namely KV2Se2O. Their findings, published in Nature Physics, highlight the promise of KV₂Se₂O both for the study of altermagnetism and for the development of spintronic devices.

Scientists have discovered a new phylum of microbes in Earth’s Critical Zone, an area of deep soil that restores water quality. Ground water, which becomes drinking water, passes through where these microbes live, and they consume the remaining pollutants. The paper, “Diversification, niche adaptation and evolution of a candidate phylum thriving in the deep Critical Zone,” is published in the Proceedings of the National Academy of Sciences.

Leonardo da Vinci once said, “We know more about the movement of celestial bodies than about the soil underfoot.” James Tiedje, an expert in microbiology at Michigan State University, agrees with da Vinci. But he aims to change this through his work on the Critical Zone, part of the dynamic “living skin” of Earth.

“The Critical Zone extends from the tops of trees down through the soil to depths up to 700 feet,” Tiedje said. “This zone supports most life on the planet as it regulates essential processes like , water cycling and , which are vital for food production, and ecosystem health. Despite its importance, the deep Critical Zone is a new frontier because it’s a major part of Earth that is relatively unexplored.”

For the better part of a century, the quantum objects known as quasiparticles have been all dressed up with nowhere to go. But that may change, now that a Yale-led team of physicists has shown it is possible to exert a greater level of control over at least one type of quasiparticle.

The discovery upends decades of fundamental science and may have wide applications for quantum-related research in the years ahead.

A is an “emergent” quantum object—a central, core particle surrounded by other particles that, together, demonstrate properties not found in each individual component. Quasiparticles have become the central conceptual picture by which scientists try to understand interacting quantum systems, including those that may be used in computing, sensors, and other devices.

A new study from the Faculty of Medicine at the Hebrew University of Jerusalem sheds light on how bacterial motion influences the spread of antibiotic resistance. Led by Professor Sigal Ben-Yehuda and Professor Ilan Rosenshine from the Department of Microbiology and Molecular Genetics, the research uncovers a direct connection between the rotation of bacterial flagella—structures used for movement—and the activation of genes that enable bacteria to transfer DNA to one another.

This process, known as bacterial conjugation, is a key mechanism by which genetic traits, particularly antibiotic resistance, are shared among bacterial populations. While conjugation has traditionally been associated with attaching to solid surfaces, the team investigated pLS20, a widespread conjugative plasmid in Bacilli species, which behaves differently. The study shows that in liquid environments, where bacteria rely on movement to navigate, the rotation of flagella acts as a mechanical signal that turns on a set of genes required for DNA transfer.

The researchers discovered that this signal triggers gene expression in a specific subset of donor cells, which then form clusters with recipient bacteria. These multicellular clusters bring the two types of cells into close contact, facilitating the transfer of genetic material.

Teleology is the idea that some processes in nature are directed toward a goal or an end. Today, it is commonly asserted that teleology is a remnant of antiquated ways of thinking about causation, and that it is not compatible with modern science, because it is fundamentally untestable.

In my opinion, such claims fail to take modern physics into account. Quantum theory involves a complex notion of causation, and it can naturally incorporate final conditions. However, to work with final conditions that are not imposed by external agents, we need to move into the realm of quantum cosmology, in which the whole universe is treated as a quantum system.

With this issue in mind, I studied final conditions in quantum cosmology. I found that cosmologies with such conditions generally predict a universe with accelerated expansion. Cosmic acceleration is a well-established fact, and also one of the most puzzling features of modern cosmology.

Lacquers, paint, concrete—and even ketchup or orange juice: Suspensions are widespread in industry and everyday life. By a suspension, materials scientists mean a liquid in which tiny, insoluble solid particles are evenly distributed. If the concentration of particles in such a mixture is very high, phenomena can be observed that contradict our everyday understanding of a liquid. For example, these so-called non-Newtonian fluids suddenly become more viscous when a strong force acts upon them. For a brief moment, the liquid behaves like a solid.

This sudden thickening is caused by the present in the suspension. If the suspension is deformed, the particles have to rearrange themselves. From an energy perspective, it is more advantageous if they roll past each other whenever possible. It is only when this is no longer possible, e.g., because several particles become jammed, that they have to slide relative to each other. However, sliding requires much more force and thus the liquid feels macroscopically more viscous.

The interactions that occur on a microscopically small scale therefore affect the entire system and they determine how a suspension flows. To optimize the suspension and specifically influence its flow characteristics, scientists must therefore understand the magnitude of the frictional forces between the individual particles.

Research teams from USTC have realized a high-performance single-photon source with an efficiency beyond the scalable linear optical quantum computing loss tolerance threshold for the first time. Led by Prof. Pan Jianwei, Lu Chaoyang and Hu Yongheng, the study was published in Nature Photonics on February 28.

Photons, as important carriers for , have the advantages of fast speed and strong resistance to environmental interference. However, for scalable linear optical quantum computing to be feasible, apart from the challenges like being easily lost, the efficiency of a source must exceed the tricky threshold of 2/3. Previous studies had never broken through this threshold, a key obstacle restricting the development of optical quantum computing.

To overcome this challenge, the research teams have developed a tunable open optical microcavity, achieving precise coupling of quantum dots and microcavities in both and spatial positioning. The microcavity solved the detuning problem of traditional fixed microcavities.

For centuries, humans have made use of glass in their art, tools, and technology. Despite the ubiquity of this material, however, many of its microscopic properties are not well understood, and it continues to defy conventional physical description.

Enter Koun Shirai of the University of Osaka. In an article published in Foundations, Shirai bridges conventional physical theory and the study of nonequilibrium materials to provide a robust description for the thermodynamics of glasses.

Most materials exist in an equilibrium state, meaning that the forces and torques on the material’s atoms are all balanced. Glasses, however, are a famous exception: they are amorphous whose atoms are always rearranging, albeit very slowly, toward an equilibrium state but do not exist in equilibrium.

Research teams have established a theoretical method for designing smooth curved wall surfaces with variable cross-section shock tubes, and developed an integrated, high-intensity multifunctional shock tube device. Led by Prof. Luo Xisheng and Prof. Si Ting from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS), the study was published in Review of Scientific Instruments.

Based on the device and techniques, the research team further developed a discontinuous perturbation interface generation technology, pioneering the experimental and mechanistic study of strong shock wave impact on single-mode fluid interface instability in shock tubes. The results were published in the Journal of Fluid Mechanics.

Shock wave-induced fluid interface instability is a common key scientific issue in aerospace vehicles and inertial confinement , while the related basic theories are still insufficient. Shock tubes are often employed to carry out basic aerodynamics research. However, the controllable generation of regularly-shaped, high-energy utilization converging and strong shock waves still remains a challenge.