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Synchronized infrared lasers control molecular shape changes and expose hidden fingerprints

Researchers from the Molecular Physics and Physical Chemistry departments of the Fritz Haber Institute have shown how two highly synchronized infrared (IR) laser beams can control molecules as they switch between different structural conformations. Their study provides a new window into how molecules rearrange themselves during chemical reactions, offering fundamental insights into the microscopic processes that govern chemistry.

Chemical reactions are the foundation of all the processes that sustain life. Researchers around the world are working to develop precise physical descriptions of these processes to better understand, predict or specifically control them.

In chemical reactions, molecules undergo various structural transformations, changing their 3D shapes between different conformations. These changes can be visualized as movements across an energy landscape, where the shape of the terrain determines how fast a reaction proceeds. Similar to a ball rolling through a hilly landscape, a molecule must overcome energy barriers—the “mountains”—to settle into a new, stable state in the next “valley.”

Diffractive networks enable optical information transfer through random and unknown diffusers

The transmission of optical information through random scattering media is a major challenge in optics, biomedical imaging, telecommunications and remote sensing. When light passes through a turbid or diffusive medium, such as biological tissue or a randomly structured optical material, the original image information can be severely distorted, making reliable recovery difficult.

Researchers at the University of California, Los Angeles (UCLA) have introduced interleaved diffractive networks to address this challenge by enabling optical information transfer through random and unknown diffusers. The work is published in the journal Laser & Photonics Reviews.

Orbitronics clears key hurdle with direct orbital currents, boosting signals 100-fold

Researchers at Johannes Gutenberg University Mainz (JGU) are the first to directly utilize orbital currents without the need for conversion of the orbital current into a spin current.

“We have thus realized the first purely orbitronic device approach,” said Dr. Christin Schmitt, a scientist in the research group of Professor Mathias Kläui at the JGU Institute of Physics.

Orbitronics is a promising technology for future memory devices, as it could enable the realization of large-scale storage media with extremely low energy consumption. It is based on orbital moments, which can be described in simplified terms as the quantum-mechanical “vortices” of electrons around atomic nuclei, as well as orbital currents, i.e., the movement of these circulations through an electrical conductor.

Spontaneous current loops in a kagome metal point to hidden quantum order

Quantum materials, materials exhibiting physical behavior governed by the laws of quantum mechanics, have proved promising for the development of numerous advanced technologies, including quantum technologies, memory devices and solar panels. In some of these materials, electrons can collectively arrange themselves in unusual patterns, giving rise to states that cannot be explained by classical physics theories.

For more than two decades, theoretical physicists have predicted the existence of a loop current order in some quantum materials. This is a state characterized by tiny electrical currents circulating around microscopic loops inside a crystal, which would produce no measurable electric current flowing through a material.

These current loops were predicted to emerge when electrons spontaneously organize themselves into a less symmetrical pattern than the crystal itself, even if atoms remain in similar positions. While this phenomenon was widely studied and described by theorists in the past, it has so far proved difficult to observe experimentally.

Airborne AI spots underwater munitions in shallow seas with high precision

A new airborne imaging approach can reliably detect unexploded weapons that lie in shallow coastal waters and remain an ongoing hazard to public safety, marine ecosystems and infrastructure worldwide. By combining advanced multispectral sensing with artificial intelligence, the researchers were able to identify underwater munitions with high confidence, even when they are partially hidden by sediment, biological growth or debris.

Scientists at the University of Miami Rosenstiel School of Marine, Atmospheric, and Earth Science developed and tested the approach and published their findings in the April issue of Frontiers in Marine Science. The study demonstrates that integrating NASA underwater imaging technologies with machine learning enhances detection accuracy while reducing false positives in complex marine environments.

“Unexploded ordnance in shallow waters remains a serious global challenge,” said Ved Chirayath, Vetlesen Endowed Chair of Earth Sciences in the Department of Ocean Sciences, the study’s lead author. “Our results demonstrate a scalable, airborne solution that can help improve detection accuracy and support safer coastal environments.”

Giving drones a sense of ‘pain’ could help them predict instability before it happens

Imagine you’re running and you sprain your ankle. The pain makes you gingerly limp the rest of the way home. This is a great example of how nature adapts to failures in a system. The pain tells you: “If you continue running like normal, the injury will only get worse.” So you naturally adjust the way you run. Drones currently cannot do this with a worn-out propeller.

Researchers from Delft University of Technology and Wageningen University & Research have now demonstrated that a concept we learned from nature, which was originally developed to predict collapse in ecosystems, can also help detect when engineered systems are heading toward failure. This is crucial for ensuring drone and autonomous vehicle safety as they increasingly become part of everyday life.

“You can compare our approach to the way humans experience pain. After an injury, pain provides immediate feedback about our condition and helps us judge what actions remain safe,” says Jasper van Beers, a researcher at Delft University of Technology. “Machines generally lack this form of self-awareness. The new indicators, derived from real-time measurement data, offer a first step toward giving engineered systems a similar ability to recognize when they are approaching their limits.”

Analog gravity advance offers new insights into Hawking radiation from black holes

Hawking radiation is a form of radiation emitted by black holes, as theoretically predicted by Stephen Hawking. It suggests that black holes do not merely swallow matter—as had previously been assumed—but also emit very faint radiation themselves. This radiation has not yet been observed in space; instead, researchers use models in the laboratory that mimic the behavior of black holes.

Although the effect of Hawking radiation is well known in astrophysics, the mechanism by which it arises in a gravitational context has not yet been fully elucidated. A scientist from Paderborn University along with an international team of researchers from the Weizmann Institute of Science in Israel and Cinvestav in Mexico is now shedding light on this mechanism using gravitational analogs in the laboratory.

The team has theoretically modeled the process by which Hawking radiation is generated in a nonlinear optical environment, identifying a simple, direct mechanism in the process. Furthermore, the team was able to observe in experiments that the radiation affects the system. The results have now been published in Nature.

Instant digital rewards may make hard thinking feel less worthwhile

Imagine opening a difficult book in a quiet room. The first page is dense. You read one paragraph, then reread it. Nothing “clicks” yet. Your brain is doing what learning often requires: spending effort before the reward arrives. Then your phone lights up. One thumb movement, and the situation changes completely. A joke, a message, a clip, a tiny social reward: all available instantly, all requiring almost no effort. The book has not become harder and, definitely, your intelligence has not disappeared. But the book now feels more expensive, because another activity nearby offers a much better bargain: reward now, effort almost zero.

That is the central idea of the paper “An Effort Recalibration Framework for Digital Media Use and Cognition” that just appeared in Nature Human Behavior. It argues that the most important effect of social media might be that repeated exposure to effortless digital rewards changes how we value effort itself. Over time, the authors suggest, digital media may recalibrate our internal sense of what effort is worth. Difficult work then begins to feel less attractive, not because we can no longer do it, but because our everyday decision system has learned to expect faster returns.

Quantum semiconductor design could expand search for dark matter

Dark matter accounts for 85% of the matter in the universe, but scientists still do not know what it is made of. A study, published in Physical Review Letters, by Rice University researchers proposes a detector design that could help search for axions, hypothetical particles that many physicists think could make up dark matter.

The proposed detector would rely on a class of semiconductor materials whose response changes when their orientation shifts within a magnetic field. This material response makes it easier to tune the detector, allowing researchers to probe a range of axion masses that have remained difficult to explore with existing technologies.

“We are proposing a well-studied material from condensed matter physics for a new application—axion detection,” said Jaanita Mehrani, a doctoral student in Rice’s Applied Physics Graduate Program who is the first author on the study. “What’s different about this material is that it doesn’t have to use complex mechanical tuning mechanisms, it simply tunes with the magnetic field.”

Quantum gravity tests may mistake ordinary spacetime for superposition

Everything around us, from atoms and molecules to planets and galaxies, is governed by two extraordinarily successful theories of physics: quantum mechanics and gravity. Quantum mechanics explains the behavior of the microscopic world, while Einstein’s theory of gravity describes the motion of stars, black holes and the expansion of the universe. Yet despite their successes, physicists are still searching for a theory of “quantum gravity” that would unite them into a single description of nature.

One of the most widely expected features of such a theory is that gravity should obey the laws of quantum mechanics. And this is where it gets difficult: Quantum mechanics predicts that any object can be delocalized over multiple places at once, which is routinely tested in experiments with atoms and even small clumps of metal. Gravity, according to Einstein’s theory, is space and time itself—it can be curved, flat or even have waves propagating through it, as confirmed by gravitational wave detectors. So many physicists believe that spacetime around a quantum object would also exist in multiple “states” simultaneously.

But what would such a situation actually look like?

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