Over the past decades, quantum scientists have introduced various technologies that operate leveraging quantum mechanical effects, including quantum sensors, computers and memory devices. Most of these technologies leverage entanglement, a quantum phenomenon via which two or more particles become intrinsically linked and share a unified quantum state, irrespective of the distance between them.
Gravitational waves are ripples in spacetime produced by violent cosmic events, such as the merging of black holes. So far, direct detections have relied on measuring tiny distance changes over kilometer-scale instruments. In a new theoretical study published in Physical Review Letters, researchers at Stockholm University, Nordita, and the University of Tübingen propose an unconventional approach: tracking how gravitational waves reshape the light emitted by atoms. The work describes a possible detection route, but an experimental demonstration remains for the future.
When atoms are excited, they naturally relax by emitting light at a characteristic frequency—a quantum process known as spontaneous emission. This happens through their interaction with the quantum electromagnetic field.
“Gravitational waves modulate the quantum field, which in turn affects spontaneous emission,” said Jerzy Paczos, a Ph.D. student at Stockholm University. “This modulation can shift the frequencies of emitted photons compared with the no-wave case.”
Since the 1960s, boron–dipyrromethene dyes, commonly called BODIPY dyes, have been widely used for their strong fluorescence, especially in bioimaging, molecular and ion sensing, and as photosensitizers. Researchers especially like how, with simple modifications to BODIPY molecules, their emission color can be tuned—an indispensable quality for multicolor imaging applications.
However, conventional BODIPY dyes are unstable in acidic environments. Strong acids can disrupt their structure by removing the boron atom and causing the dye to lose its fluorescence. This has limited their use in highly acidic conditions.
In a new breakthrough, researchers from Hokkaido University have developed a superacid-resistant BODIPY dye. The research team, led by Professor Yasuhide Inokuma at the Institute for Chemical Reaction Design and Discovery (WPI-ICReDD), reports the findings in Nature Communications.
Skyrmions, in which electron spins inside a magnet are arranged like vortices, are a key structure in next-generation spintronics technology. KAIST researchers have shown that skyrmions can form using only the fundamental physical interactions within magnets, without requiring special physical conditions.
This finding, published in the journal Physical Review Letters, expands the possibility of realizing skyrmions in a wide range of magnetic materials and suggests new potential for developing next-generation ultra-low-power information devices with data storage densities tens to hundreds of times higher than current technologies.
A research team led by Professor Se Kwon Kim from the Department of Physics has proposed a new theoretical framework showing that vortex-like magnetic structures can naturally emerge solely through magnetoelastic coupling —the interaction between magnetism and lattice structure.
The search isn’t over—future runs of the High-Luminosity LHC and the proposed Future Circular Collider (FCC) will continue to hunt for these “inert” twins to see if they are hiding at even higher energy levels.
For the first time ever, the CMS experiment has designed a dedicated analysis using parametrised machine learning to look for new dark particles that don’t socialize with Standard Model fermions, one of them being a favourite candidate in the search for dark matter.
Using proton-proton collisions delivered by the LHC in 2016–2018 and 2022, CMS collaborators have been looking for new scalar particles in a theoretical framework that had never before been tested with a dedicated analysis, leading to the widest excluded mass range to date for this model.
Are there more Higgs-boson-like particles?
Having found a Higgs boson (a scalar particle), theorists naturally ask themselves: could there be more than one? In fact, rather than a single Higgs boson, which is the only observable particle, the Standard Model predicts a so-called Higgs doublet. While we’re at it, let’s add a second electroweak doublet; why not? The effect is the conception of 4 new scalar particles: two neutral ones, labeled H and A (with H the lightest of the two), and two charged ones, H+ and H-. The search for such extra scalar particles has already spanned several decades, but only when they actually interact with our Standard Model particles. With an extra ingredient, called the ℤ2 symmetry, the new scalars become allergic to our matter particles, the fermions, and only prefer to talk to bosons like themselves: the Higgs boson, but also the W and Z bosons. They become so-called inert, or dark, scalars and the model inherits this name — the Inert Doublet Model.
What will the computers of tomorrow look like? Chances are good that spintronics will play a decisive role in the next generation of computers. In spintronics, the intrinsic angular momentum of an electron (the spin) is used to store, process and transmit data. This technology is already in use today, for example in hard drives. However, the scope of what is possible extends much further: More recent approaches aim at using not just individual spins, but entire spin waves made up of partly hundreds of trillions of spins. Such collective spin excitations are known as magnons. They could enable extremely energy-efficient data transmission—even in the terahertz range.
So far, so good. But how can these spin waves be coupled to today’s technology? “If we develop a concept to perform computer calculations with magnons, it must be compatible with the technology we currently use,” says physicist Davide Bossini from the University of Konstanz. “To reach this goal, you have to convert the spin wave into an electrical charge signal.” This spin-to-charge conversion is one of the major challenges of spintronics.
Glass appears to be a solid, but in theory it sometimes behaves more like an extremely slow liquid. Physicists in Utrecht now show that glass-like structures can also exist in equilibrium, which is something many theories say should be impossible.
The bottom parts of medieval window panes, such as those in old cathedrals, are often thicker than the top. Has the material slowly flowed downward over the centuries, and does this mean that glass actually flows? This is a persistent myth, and the explanation lies in the way glass was produced in the Middle Ages. Because window panes were made by hand, their structure was often irregular and contained thinner and thicker parts. The panes were usually installed in the frame with the thicker side at the bottom, which made them more stable.
Still, the story touches on a real physics question. What glass actually is, a solid or a very slow liquid, turns out to be more difficult to answer than it seems.
An international collaboration, including Northwestern University, has reached a critical milestone in the search for dark matter, the mysterious substance that makes up about 85% of all matter in the universe. Located two kilometers below ground in Canada, the Super Cryogenic Dark Matter Search (SuperCDMS) at SNOLAB has cooled to its operating temperature, the collaboration announced on March 17.
Just thousandths of a degree above absolute zero, the cryogenic experiment is about 100 times colder than the temperature of deep space. This extreme cold enables scientists to eliminate thermal noise from vibrating atoms, potentially isolating dark matter’s incredibly tiny signals.
With this milestone, the project transitions from building the experiment to preparing for the search. Researchers can now turn on the dark matter detectors, whose superconducting sensors only function when cooled to extremely low temperatures. If the equipment operates correctly, it should achieve the highest level of sensitivity yet for detecting low-mass particles, which have about half the mass of a single proton.
