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Monitoring sediment buildup in underwater bridge tunnels with the help of high-energy muons

Over 200 underwater bridge tunnels exist for vehicular traffic around the world, providing connectivity between cities. Once constructed, however, these tunnels are difficult to monitor and maintain, often requiring shutdowns or invasive methods that pose structural risks.

Muography—an using , called , which can traverse hundreds of meters within the Earth—can provide a noninvasive approach to examining subterranean infrastructure.

In the Journal of Applied Physics, a group of researchers from public and private organizations in Shanghai applied this technique to the Shanghai Outer Ring Tunnel, which runs under the Huangpu River as part of the city’s ring expressway.

Ultrathin films of ferromagnetic oxide reveal a hidden Hall effect mechanism

Researchers from Japan have discovered a unique Hall effect resulting from deflection of electrons due to “in-plane magnetization” of ferromagnetic oxide films (SrRuO3). Arising from the spontaneous coupling of spin-orbit magnetization within SrRuO3 films, the effect overturns the century-old assumption that only out-of-plane magnetization can trigger the Hall effect.

The study, now published in Advanced Materials, offers a new way to manipulate with potential applications in advanced sensors, , and spintronic technologies.

When an electric current flows through a material in the presence of a magnetic field, its electrons experience a subtle sideways force which deflects their path. This effect of electron deflection is called the Hall effect—a phenomenon that lies at the heart of modern sensors and electronic devices. When this effect results from internal magnetization of the conducting material, it is called “anomalous Hall effect (AHE).”

An AI model can forecast harmful solar winds days in advance

Scientists at NYU Abu Dhabi (NYUAD) have developed an artificial intelligence (AI) model that can forecast solar wind speeds up to four days in advance, significantly more accurately than current methods. The study is published in The Astrophysical Journal Supplement Series.

Solar wind is a continuous stream of charged particles released by the sun. When these particles speed up, they can cause “space weather” events that disrupt Earth’s atmosphere and drag satellites out of orbit, damage their electrons, and interfere with power grids. In 2022, a strong event caused SpaceX to lose 40 Starlink satellites, showing the urgent need for better forecasting.

The NYUAD team, led by Postdoctoral Associate Dattaraj Dhuri and Co-Principal Investigator at the Center for Space Science (CASS) Shravan Hanasoge, trained their AI model using high-resolution ultraviolet (UV) images from NASA’s Solar Dynamics Observatory, combined with historical records of solar wind.

Machine learning unravels quantum atomic vibrations in materials

Caltech scientists have developed an artificial intelligence (AI)–based method that dramatically speeds up calculations of the quantum interactions that take place in materials. In new work, the group focuses on interactions among atomic vibrations, or phonons—interactions that govern a wide range of material properties, including heat transport, thermal expansion, and phase transitions. The new machine learning approach could be extended to compute all quantum interactions, potentially enabling encyclopedic knowledge about how particles and excitations behave in materials.

Scientists like Marco Bernardi, professor of applied physics, physics, and at Caltech, and his graduate student Yao Luo (MS ‘24) have been trying to find ways to speed up the gargantuan calculations required to understand such particle interactions from first principles in real materials—that is, beginning with only a material’s atomic structure and the laws of quantum mechanics.

Last year, Bernardi and Luo developed a data-driven method based on a technique called singular value decomposition (SVD) to simplify the enormous mathematical matrices scientists use to represent the interactions between electrons and phonons in a material.

New laser technique reveals nearly 20 previously hidden states of matter

In 2023, physicist Xiaodong Xu at the University of Washington —working with researchers from Cornell and Shanghai Jiao Tong University —found that twisting atom-thin layers of molybdenum ditelluride into a special pattern called a moiré lattice could produce the fractional quantum anomalous Hall effect without magnets. This was a huge leap, because magnets can disrupt superconducting materials used in quantum technology.

Xu’s team discovered two such magnet-free fractional states. That alone was remarkable. But Zhu and his colleagues suspected there were more waiting to be found. The secret lies in the moiré pattern. When the layers are slightly rotated relative to each other, they form a honeycomb-like grid at the atomic scale.

This structure changes the way electrons move, encouraging them to team up in unusual ways that create fractional charges. In other words, the twist turns the material into a playground for exotic quantum phases.

From carbon particles to diamonds: a Japanese innovation breaks the rules

A Japanese research team has rewritten the rules of diamond creation, turning carbon molecules into flawless diamond nanoparticles without the furnace-like heat or crushing pressure usually required. Led by the University of Tokyo, this breakthrough uses an electron beam to unlock what was once thought impossible—and it could change how scientists image and analyze matter forever.

Published on September 4 in the journal Science, this pioneering work could revolutionize material science and open new doors in technology. But beyond the technical marvel lies a profound shift in understanding how organic molecules react under electron beams.

China may soon lead the global race to mine minerals from the ocean floor

Atomic ‘CT scan’ reveals how gallium boosts fuel cell catalyst durability

Hydrogen fuel cell vehicles have long been hailed as the future of clean mobility: cars that emit nothing but water while delivering high efficiency and power density. Yet a stubborn obstacle remains. The heart of the fuel cell, the platinum-based catalyst, is both expensive and prone to degradation. Over time, the catalyst deteriorates during operation, forcing frequent replacements and keeping hydrogen vehicles costly.

Understanding why and how these catalysts degrade at the atomic level is a longstanding challenge in catalysis research. Without this knowledge, designing truly durable and affordable fuel cells for mass adoption remains out of reach.

Now, a team led by Professor Yongsoo Yang of the Department of Physics at KAIST (Korea Advanced Institute of Science and Technology), in collaboration with Professor Eun-Ae Cho of KAIST’s Department of Materials Science and Engineering, researchers at Stanford University and the Lawrence Berkeley National Laboratory, has successfully tracked the three-dimensional change of individual atoms inside fuel cell catalysts during thousands of operating cycles. The results provide unprecedented insight into the atomic-scale degradation mechanisms of platinum-nickel (PtNi) catalysts, and demonstrate how gallium (Ga) doping dramatically improves both their performance and durability.

New neutrino detector in China is coming online

Neutrinos are one of the most enigmatic particles in the standard model. The main reason is that they’re so hard to detect. Despite the fact that 400 trillion of them created in the sun are passing through a person’s body every second, they rarely interact with normal matter, making understanding anything about them difficult. To help solve their mysteries, a new neutrino detector in China recently started collecting data, and hopes to provide insight on between forty and sixty neutrinos a day for the next ten years.

The detector, known as the Jiangmen Underground Neutrino Observatory, or JUNO, is located in between two huge nuclear plants at Yangjian and Taishan. Both of those fission plants create their own artificial neutrinos in addition to the ones created by the sun, meaning the general area should be awash with barely interacting particles.

That’s despite the fact that, like most , it’s located underground. 700 meters underground, in fact. The physical bulk of Earth’s crust is meant to block most other particles, like muons, from getting to it, and at other installations, like IceCube, it does a pretty good job.

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