Toggle light / dark theme

Get the latest international news and world events from around the world.

Log in for authorized contributors

A new route to electrically controlled helimagnetic structures

Advanced magnetic memory and spintronic devices rely on the ability to control magnetic states using electricity. Today, such technologies work by manipulating relatively simple magnetic structures found in ferromagnets, where all the magnetic moments point the same way. However, researchers are becoming increasingly interested in controlling more complex magnetic systems because these could offer higher information density and improved efficiency.

Helimagnets are a prime example of such systems. In these materials, the magnetic moments form spiral or helical patterns that wind through the material. The direction in which these magnetic patterns propagate plays an important role in determining the material’s electrical and magnetic behavior.

However, researchers had not established a reliable way to reversibly control the orientation of helical magnetic structures using an electric current, and current-driven techniques developed for ferromagnets do not directly carry over to helimagnetic systems.

Capturing the cosmic ‘drift’ before a star is born

Stars like our sun are formed from the collapse of stellar objects called prestellar cores, cold and dense concentrations of gas and dust held together by gravity. While many questions remain about the exact mechanisms of star formation, advanced radio telescopes have given researchers new insights into the inner workings of infant stars.

Now, publishing in Astronomy & Astrophysics, researchers from Kyushu University and Max Planck Institute for Extraterrestrial Physics have, for the first time, detected a phenomenon known as ambipolar diffusion occurring in a prestellar core. This phenomenon weakens the magnetic support of the core, leading to gravitational collapse to form an infant star called a protostar.

These findings provide further insight into the key processes of early star formation and, by extension, how stellar systems are created.

Evidence reveals that the language of thought is not natural language

Some people find it useful to talk through their problems—but language isn’t necessary for logical reasoning, cognitive neuroscientists at MIT’s McGovern Institute for Brain Research say.

In research published in the journal PNAS, researchers led by MIT associate professor of brain and cognitive sciences Evelina Fedorenko have shown that people can perform well on tasks that require logical reasoning even if their language abilities are severely impaired. What’s more, brain imaging shows that language-processing parts of the brain are not called on for logical reasoning.

Philosophers, linguists and cognitive scientists have debated the relationship between language and thought for thousands of years, with many arguing that we use language to think. There are good reasons to suspect a close relationship between logic and language, acknowledges Hope Kean, a postdoctoral researcher and former K. Lisa Yang, Integrative Computational Neuroscience (ICoN) Center graduate fellow in Fedorenko’s lab.

AI identifies new particle models that may explain neutrinos’ tiny mass

Physicists at the University of California, Irvine, have developed an artificial intelligence system that can autonomously design theoretical physics models, a task traditionally carried out by human theorists. The approach allows researchers to explore large, uncharted areas of particle physics theory, helping identify promising new explanations for the behavior of neutrinos.

The system is called Autonomous Model Builder (AMBer), and was developed by a research team led by UC Irvine doctoral candidates Victoria Knapp-Pérez and Jake Rudolph in the Department of Physics and Astronomy. The work is published in Communications Physics.

AMBer uses reinforcement learning, a form of artificial intelligence that learns through trial and error rather than by following predefined instructions. As it explores possible particle physics theories, the system evaluates its own choices and improves over time.

Quantum optics may turn this rare visual phenomenon into an eye test

Modern life depends on quantum physics. It makes technologies such as GPS navigation, MRI scanners and computer chips possible. Now, the same science may also lead to a new way to test the health of our eyes. A University at Buffalo-led team has used a technique from quantum optics to make a little-known visual pattern produced inside the eye easier to see—potentially opening the door to a new way to test retinal health.

Known as Boehm’s brushes, these faint, two-lobed, bowtie-shaped patterns sometimes appear in peripheral vision when polarized light scatters off structures in the retina. Because people with retinal disease may be less likely to perceive them, scientists have long wondered whether they could serve as a biomarker of retinal health.

However, Boehm’s brushes are often too hard to see, even for people with healthy eyes, to be useful in clinical practice.

Programmable light simulates quantum matter across 300 processes without bigger circuits

A team of researchers at the University of Ottawa and its Nexus for Quantum Technologies Institute, in collaboration with researchers from Federico II University in Italy, has developed a programmable quantum simulator that shapes a beam of light to replicate how particles move through complex materials, avoiding the need for ever-larger electronic hardware.

Neutron imaging reveals how water limits CO₂ storage in recycled concrete

The construction sector faces two problems at once: it emits large amounts of CO₂ and produces vast quantities of concrete waste. But what if part of that waste could be used to trap carbon instead of ending up as rubble?

That is the idea behind accelerated carbonation.

Crushed recycled concrete can be exposed to CO₂-rich gas, allowing carbon dioxide to react with the old cement paste and become locked into stable mineral compounds. In principle, this could help reduce the environmental impact of construction while giving demolition waste a second life.

Quantum material opens new path for studying unusual electronic behavior

The work lays the foundation to build a new platform to explore phenomena that could power devices capable of transporting and grouping electrical signals and quantum states in ways not traditionally achievable without relying on optical or engineered systems. The team detailed its findings in a paper published in Science Advances.

Non-Hermitian physics refers to systems that exhibit behaviors not found in conventional physical models, explained Morteza Kayyalha, assistant professor of electrical engineering at Penn State and corresponding author on the paper. These systems can display unusual behaviors, such as enhanced responses to perturbations and external stimuli. They can also demonstrate the non-Hermitian skin effect, where quantum states—which researchers can use to predict the physical properties of a material—become concentrated near a specific boundary or point in the material, rather than spreading uniformly throughout.

Check your ingredients’: A new blueprint for using Fermi’s ‘Golden Rule

Underpinning much of modern technology, from smartphones to scanning tunneling microscopes to particle colliders, is Fermi’s Golden Rule. Named for 20th-century Italian American physicist Enrico Fermi (but actually discovered by British physicist Paul Dirac), the rule is a formula that connects what can be measured in an experiment—such as how fast atoms “jump” between energy states—to the microscopic properties of a quantum mechanical system. The formula is taught in every undergraduate quantum physics class.

Yet scientists sometimes misapply it. They either misjudge the conditions under which the formula works, or they miss the “window” for its use. A “user manual” for Fermi’s Golden Rule would be a boon to researchers, says Yale physicist Nir Navon—and now he and his lab partners have provided one.

“We put one of the most famous formulas in all of quantum mechanics to the test, and found where it works and where it fails, including ways that many physicists weren’t fully aware of,” said Navon, an associate professor of physics in Yale’s Faculty of Arts and Sciences and senior author of a new study published in the journal Nature Physics. “We’re telling everyone who uses it to take a breath first and check their ingredients.”

Using mechanical vibrations instead of magnetic memory for quantum computing

Quantum computers still face limits when it comes to storing information. Researchers at ETH Zurich are now turning to mechanical vibrations rather than electromagnetic memory. Their new vibrating memory can store significantly more information in a smaller volume. Combined with a suitable computer architecture, it also enables the efficient solution of complex computational problems.

The computer works almost like a guitar. The ETH Zurich quantum physicist Yiwen Chu and her team use tiny mechanical vibrations to store and process information. These vibrations behave much like the vibrating strings of a guitar, which produce musical notes.

What sounds like music is, in fact, quantum physics. The vibrations that Chu and her team work with are far beyond the range of human hearing. They occur deep inside a quantum chip, where they are used to store quantum information.

/* */