Controlling magnetism in a device is not easy; unusually large magnetic fields or lots of electricity are needed, which are bulky, slow, expensive and/or waste energy. But that looks soon to change, thanks to the recent discovery of altermagnets. Now scientists are putting forth ideas for efficient switches to manage magnetism in devices.
Magnetism has traditionally come in two varieties: ferromagnetism and antiferromagnetism, based on the alignment (or not) of magnetic moments in a material. Early last year, physicists announced experimental evidence for a third variety of magnetism: altermagnetism, a different combination of spins and crystal symmetries. Researchers are now learning how to tune altermagnets, bringing science closer towards practical applications.
We’re all familiar with ferromagnetism (FM), like a refrigerator magnet or compass needle, where magnetic moments in atoms lined up in parallel in a crystal. A second class was added about a hundred years ago called antiferromagnetism (AFM), where magnetic moments in a crystal align regularly in alternate directions on differing sublattices, so the crystal has no net magnetization, but usually does at low temperatures.
Until now, creating quantum superpositions of ultra-cold atoms has been a real headache, too slow to be realistic in the laboratory. Researchers at the University of Liège have now developed an innovative new approach combining geometry and “quantum control,” which drastically speeds up the process, paving the way for practical applications in quantum technologies.
The paper is published in the journal Physical Review A.
Imagine being in a supermarket with a cart filled to the brim. The challenge: get to the checkout before the others, without dropping your products on the corners. The solution? Choose a route with as few corners as possible to go faster without slowing down. That’s exactly what Simon Dengis, a doctoral student at the University of Liège, has managed to do, but in the world of quantum physics.
In a remarkable leap forward for science, researchers at CERN have successfully created and observed top quarks—one of nature’s most elusive and unstable particles—inside a lab for the very first time. This breakthrough, announced by the ATLAS team at the Large Hadron Collider (LHC), promises to reshape our understanding of the early Universe and the fundamental makeup of matter.
Quantum critical points are thresholds that mark the transition of materials between different electronic phases at absolute zero temperatures, around which they often exhibit exotic physical properties.
One of these critical points is the so-called Kondo-breakdown quantum critical point, which marks the collapse of the Kondo effect (i.e., quantum phenomenon that entails the localization of magnetic moments in metals), followed by new emergent physics.
Researchers at Ludwig-Maximilian University of Munich, Rutgers University, and Seoul National University set out to further study the dynamical scaling associated with the Kondo-breakdown quantum critical point, utilizing a theoretical framework describing heavy fermion materials known as the periodic Anderson model.
Hydrogen is increasingly gaining attention as a promising energy source for a cleaner, more sustainable future. Using hydrogen to meet the energy demands for large-scale applications such as utility infrastructure will require transporting large volumes via existing pipelines designed for natural gas.
But there’s a catch. Hydrogen can weaken the steel that these pipelines are made of. When hydrogen atoms enter the steel, they diffuse into its microstructure and can cause the metal to become brittle, making it more susceptible to cracking. Hydrogen can be introduced into the steel during manufacturing, or while the pipeline is in service transporting oil and gas.
To better understand this problem, researcher Tonye Jack used the Canadian Light Source (CLS) at the University of Saskatchewan (USask) to capture a 3D view of the cracks formed in steels. Researchers have previously relied on two-dimensional imaging techniques, which don’t provide the same rich detail made possible with synchrotron radiation.
A joint research team has successfully developed a next-generation soft robot based on liquid. The research was published in Science Advances.
Biological cells possess the ability to deform, freely divide, fuse, and capture foreign substances. Research efforts have long been dedicated to replicating these unique capabilities in artificial systems. However, traditional solid-based robots have faced limitations in effectively mimicking the flexibility and functionality of living cells.
To overcome these challenges, the joint research team successfully developed a particle-armored liquid robot, encased in unusually dense hydrophobic (water-repelling) particles.
One of the key takeaways from the experiment is that quantum mechanics does not conform to classical expectations. By creating a GHZ-type paradox in 37 dimensions, the researchers demonstrated a breakdown of local realism in ways previously unexplored.
In classical terms, the paradox suggests that an event could occur without a causative link—like a letter appearing in your mailbox without a postal worker delivering it. In quantum terms, the experiment showed that the relationship between entangled particles was so deeply nonlocal that their correlations could not be explained by any hidden variables.
The research team mathematically confirmed that their experiment achieved the strongest recorded manifestation of quantum nonlocality. By showing that the paradox holds true even under extreme conditions, they provided new evidence that classical models fail to explain the quantum world.
In late 2023, Wojciech Brylinski was analyzing data from the NA61/SHINE collaboration at CERN for his thesis when he noticed an unexpected anomaly—a strikingly large imbalance between charged and neutral kaons in argon–scandium collisions. He found that, instead of being produced in roughly equal numbers, charged kaons were produced 18.4% more often than neutral kaons.
This suggested that the so-called “isospin symmetry” between up and down quarks might be broken by more than expected due to the differences in their electric charges and masses—a discrepancy that existing theoretical models would struggle to explain. Known sources of isospin asymmetry only predict deviations of a few percent.
“When Wojciech got started, we thought it would be a trivial verification of the symmetry,” says Marek Gaździcki, who was spokesperson of NA61/SHINE at the time of the discovery. “We expected the symmetry to be closely obeyed—although we had previously measured these types of discrepancies at the NA49 experiment, they had large uncertainties and were not significant.”