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Framework unifies the classical and quantum Mpemba effects

Physicists have developed a new theoretical framework which unifies a wide array of seemingly unrelated “Mpemba effects”: counterintuitive cases where systems driven further from equilibrium relax faster than those closer to it. Reporting their results in Physical Review X, researchers led by John Goold at Trinity College Dublin show that both classical and quantum versions of the effect can be understood using the same underlying logic—resolving a long-standing conceptual puzzle.

In 1963, 13-year-old Tanzanian student Erasto Mpemba noticed that when he placed an ice cream mixture in the freezer while it was still hot, it froze faster than the other, initially cooler mixtures in the freezer. His observation was later confirmed in 1969 through a study involving Mpemba, together with physicist Denis Osborne.

Since then, effects analogous to the Mpemba effect have been observed in transitions ranging from crystallizing polymers to transitions in magnetic materials. Yet despite close experimental scrutiny, the mechanisms underlying the effect remained elusive.

Light switch for life: Controlling molecular droplets with UV

Biomolecular condensates are tiny, droplet-like structures made up of molecules that help organize key processes in living organisms. Because they are so small and constantly changing, it has been difficult for scientists to measure their physical properties or control how they behave. Leiden researchers at the Mashaghi Lab have now discovered a surprising new way to shape and control tiny droplets of molecules found in living organisms. The breakthrough could lead to smarter biomaterials, improve drug delivery and even new insights into the emergence of life on Earth. The work is published in Nature Communications.

“Our lab works at the interface of biophysics, molecular engineering and medicine,” says Alireza Mashaghi. “We explore how molecular interactions drive the emergent properties of biological materials.”

Inside the condensates, Mashaghi and his team triggered a reaction normally associated with DNA damage from UV light (like that seen in skin cancer). Known as thymine dimer formation, this process causes two neighboring thymine bases to bond together. By harnessing this reaction as a molecular “switch” within the condensates, the researchers were able to alter the internal connectivity of the molecules, allowing them to control how the condensates behave.

Next-generation optical sensor can read photon spin across UV-to-infrared wavelengths

A research team led by Professor Jiwoong Yang of the Department of Energy Science and Engineering at DGIST has developed next-generation optical sensor technology capable of precisely detecting not only the intensity and wavelength of light but also its rotational direction—the spin information of photons. The team successfully implemented a quantum-dot-based optical sensor that can detect circularly polarized light (CPL) across an ultra-wide spectral range—from ultraviolet to short-wave infrared—demonstrating photodetection performance comparable to that of commercial silicon optical sensors. The paper is published in Advanced Materials.

CPL refers to light in which the electric field rotates helically as it propagates. This is directly linked to the spin information of photons—the fundamental particles of light. This polarization information serves as a crucial signal in next-generation security and communication technologies, such as quantum communication, quantum cryptography, and photonic quantum information processing, which is why related optical sensor technologies are attracting significant worldwide attention.

Conventional circularly polarized light sensors typically require the light-absorbing material itself to possess a specific helical orientation, known as a chiral structure. This approach not only limits the range of usable materials but also confines detection to narrow spectral regions, such as ultraviolet or visible light. Extending this technology into the infrared region, which is essential for quantum communication and optical sensing, has previously posed a major technical challenge.

Earth formed from material exclusively from the inner solar system, planetary scientists show

Planetary scientists have long debated where the material that formed Earth comes from. Despite its location in the inner solar system, they consider it likely that 6–40% of this material must have come from the outer solar system, i.e., beyond Jupiter. For a long time, material from the outer solar system was considered necessary to bring volatile components such as water to Earth. Accordingly, there must also have been an exchange of material between the outer and inner solar systems during the formation of Earth. But is that really true?

Planetary scientists Paolo Sossi and Dan Bower, from ETH Zurich, compared existing data on the isotopic ratios of a wide range of meteorites, including those from Mars and the asteroid Vesta, with those of Earth. Isotopes are sibling atoms of the same element (same number of protons) that have a different mass (different number of neutrons).

The researchers analyzed this data in a new way and arrived at a surprising conclusion: the material that makes up Earth originates entirely from the inner region of the solar system.

Strained liquid crystals steer soliton ‘bullets’ along two diagonal paths

In physics, some waves behave in a surprising way: instead of spreading out and fading, they hold their shape as they travel at constant speeds. These unusual waves, called solitons, have interested scientists since they were first observed in canals in the 19th century. Today, researchers study solitons in everything from optical fibers to biological systems.

A new study published in Proceedings of the National Academy of Sciences, shows that these stubborn waves can be guided and steered through materials by carefully designing internal strain, offering new ways to move energy or information at microscopic scales.

What’s inside a masterpiece? Laser scans and AI map paint layers molecule by molecule

Paintings are far more than dabs of oil on canvas. They are complex works of art composed of multiple layers, from primer and glues to the pigments and protective varnishes applied by the artists. Being able to see into these layers and map their chemical makeup is essential for art historians and conservators. A new technique developed by an international team of scientists can now probe paint layers in far greater molecular detail than before.

As they describe in a paper published in the journal Science Advances, the researchers combined a technique called MALDI-MSI (matrix-assisted laser desorption/ionization mass spectrometry imaging) with an AI named MSIpredictART to help identify the specific pigments and binders present in each layer of a painting.

Current approaches looking at the internal structure of a painting have to run several different tests on tiny samples. MALDI-MSI reduces the need for multiple separate techniques by using a high-resolution laser scan to map both the pigments and the binder or glue that holds them together.

Stabilized laser components could shrink quantum computers from room- to chip-scale

Scientists in the Riccio College of Engineering at the University of Massachusetts Amherst and the University of California Santa Barbara have demonstrated key laser and ion trap components necessary to help drastically shrink the size of quantum computers, an achievement aligned with the shrinking of integrated microprocessors in the 1970s, 80s and 90s that allowed computers to move from room-sized behemoths to today’s ultrathin smartphones.

The current state-of-the-art technology for quantum computing is too large and complex to scale and too sensitive and bulky to be portable. The largest and most sensitive components of these quantum systems are the optics, which include multiple lasers and vibration-isolated, temperature-controlled vacuum chambers that contain ultrastable optical cavities. These cavities stabilize the lasers to extremely high precision in order to control trapped ions for quantum computing and optical clocks.

Graphene ‘leaf tattoo’ sensor tracks plant hydration in real time

Is your houseplant thirsty? Are crops getting enough water? Is a forest at high risk of wildfire? Leaf health can answer all these questions, and researchers at The University of Texas at Austin have developed new technology to measure hydration levels with greater accuracy and without hurting the plant. The researchers developed an electronic tattoo for leaves that uses the hyperflexible and sustainable material graphene to track hydration levels. It sticks on the leaves without harming them, a major improvement over current methods that work only with dead or dried-out leaves or provide indirect measurements.

“Being able to directly measure and monitor the live leaf over time, at the point of photosynthesis, gives us more information to understand the health of our plant ecosystems, whether that’s an individual plant or an entire forest,” said Jean Anne Incorvia, associate professor in the Cockrell School of Engineering’s Chandra Family Department of Electrical and Computer Engineering and one of the leaders on the new research published recently in Nano Letters.

Hygroscopic salts pull lithium from mining waste using only moisture from air

The world cannot have enough of the third element on the periodic table. From smartphones and laptops to state-of-the-art EVs, all are powered by lithium batteries. The demand for metal is only going to rise, and projected values suggest nearly a triple increase in demand by 2030. The traditional process of lithium mining is both water and energy-hungry. One such step is the dissolution of lithium salts from other competing minerals during the separation process.

In a study published in Nature Communications, researchers present a clever way to harness the deliquescence of lithium chloride hydrate (LHT)—a unique ability to naturally pull moisture from the air to dissolve itself—to extract and concentrate lithium from mining waste while leaving behind unwanted minerals.

The method achieved up to 97% lithium recovery with an increase in the lithium purity by 1,500 times, producing a liquid concentrate with lithium levels reaching 97,000 parts per million, which was more than twice as concentrated as the standard solutions used in battery processing.

Three-in-one diode integrates sensing, memory and processing for smart cameras

Think about how easily you recognize a friend in a dimly lit room. Your eyes capture light, while your brain filters out background noise, retrieves stored visual information, and processes the image to make a match. It all happens in a fraction of a second and uses remarkably little energy. Unfortunately, artificial vision systems in smartphones, cameras, and autonomous machines operate more like an assembly line. In our recent paper published in Nature Electronics, we describe how we addressed this challenge by enabling sensing, memory, and processing within the same device, pointing to a possible route toward more efficient machine vision.

The iGaN Laboratory led by Professor Haiding Sun at the School of Microelectronics, University of Science and Technology of China (USTC), in collaboration with multiple institutions, developed the multifunctional semiconductor diode with integrated photosensing, memory, and processing capabilities.

To understand the challenge, it helps to look at the basic building block of modern digital cameras: the semiconductor p-n diode. These tiny junctions act as the light-sensing pixels in imaging systems. However, a conventional diode is usually limited to a single function. It converts light into an electrical signal, and the captured data must then be transferred to separate memory and processing units. Moving this data back and forth consumes time, power, and chip area.

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