Three RIKEN researchers have demonstrated a way to stop problematic “dark modes” from squelching intriguing effects in quantum systems. This advance could help with the development of more versatile quantum devices that can be used to control the storage and transmission of quantum information. The study is published in the journal Nature Communications.
Manipulations that alter the topology of certain quantum systems known as non-Hermitian systems are attracting increasing attention, since they offer novel possibilities for manipulating particles of sound (phonons) and light (photons) as well as other excitations.
“Topological operations allow for various weird and fascinating phenomena, such as the buildup of chiral phases and the movement of phonons in one direction,” notes Franco Nori of the RIKEN Center for Quantum Computing (RQC).
An unprecedented neutrino detection in the Mediterranean has pushed the boundaries of high-energy astrophysics, raising new questions about the most extreme processes in the universe.
Some innovations in physics come from entirely new technologies, others from fresh theoretical insights. Others still take shape by bringing together existing tools in new ways, working out how to combine them to outperform other solutions. The branch of particle physics that studies weakly interacting particles—such as neutrinos and some types of dark-matter candidates—could use innovative detection approaches: technological challenges in this research area quickly become practical as well as economic, as increases in detector volume and spatial resolution improve the sensitivity to the processes producing the particles of interest. Similarly, demanding targets on instrument capability apply to the calorimeters used in collider experiments.
Three-dimensional (3D) tracking of elementary particles in large-volume, dense materials is required in most particle physics experiments. In a scintillator, this is commonly achieved through fine segmentation of the material into many smaller active units, with each unit emitting light in the visible frequency range when a charged particle passes through it. Typically, the photons produced in every active unit are collected by optical fibers and carried outside of the scintillator to the photomultiplier tubes or silicon photomultipliers used for photon counting.
In the T2K neutrino-oscillation experiment in Japan, for example, one detector boasts about two tons of sensitive volume assembled from approximately two million cubes and 60,000 fibers. Over at CERN and the Paul Scherrer Institute, the LHCb and Mu3e experiments achieve sub-millimeter spatial resolution thanks to millions of thin scintillating optical fibers. With these figures, it’s clear that the scalability of this kind of scintillator material segmentation may turn into a bottleneck when larger volumes become necessary.
Urea is an extremely important chemical, especially for fertilizers. But, making urea is energy intensive and relies heavily on fossil fuels. However, new findings from Griffith University and the Queensland University of Technology have highlighted new ways to produce urea electrochemically, using electricity and waste gases such as carbon monoxide (CO) and nitrogen oxides (NO) instead.
The paper, “Machine Learning-Assisted Design Framework of Carbon Edge-Dominated Dual-Atom Catalysts for Urea Electrosynthesis,” has been published in ASC Nano.
“The challenge is that when CO and NO react on a catalyst, they usually don’t form urea,” said co-lead author Professor Qin Li from Griffith University.
When you throw a ball in the air, the equations of classical physics will tell you exactly what path the ball will take as it falls, and when and where it will land. But if you were to squeeze that same ball down to the size of an atom or smaller, it would behave in ways beyond anything that classical physics can predict.
Or so we’ve thought.
MIT scientists have now shown that certain mathematical ideas from everyday classical physics can be used to describe the often weird and nonintuitive behavior that occurs at the quantum, subatomic scale.
The fundamental quantum postulates on the existence of a wave function, its propagation with the Schrödinger equation in theorem 3.2 and the wave collapse at a measurement in lemma 3.3 are derived from the classical theorem 2.4. Furthermore, analytic computations of the classical action are simpler than solving the Feynman path integral and potentially easier than solving the Schrödinger equation directly. In addition, theorem 3.2 is a multi-particle result.
The J classical multipaths in theorem 3.2 and lemma 3.3 are strictly determined by the initial and final conditions. In the double slit experiment, the probabilistic quantum observation results from the non-Lipschitz constraint force in the slit. For the harmonic oscillator, the Coulomb wave, the particle in the box, or the spinning particle, the initial probabilistic density distribution is classically propagated forward in time. In the EPR experiment [64,65], theorem 2.4 determines a constant angular momentum χo↑,χo↓ over time, and lemma 3.3 in turn allows a classical interpretation that the decision which spin correlation is sensed behind the filters is already taken when the particles separate.
Daniel de Florian had already established himself as a theoretical physicist—leading a group at CERN that contributed to the discovery of the Higgs boson—when he had an idea: introducing physics into high schools using virtual reality (VR). He believed that younger generations were drawn to less traditional ways of accessing science and that VR might be worth a try. As director of the Institute of Physical Sciences at the National University of General San Martín, located on the outskirts of the sprawling metropolis of Buenos Aires in Argentina, he had the resources to pursue the idea.
In 2024, de Florian began developing a combination of science, gaming, and immersive technology to create a VR-boosted version of high school physics courses. With funding from an international bank, he conducted the first pilot tests in 2025. In the VR program, students could manipulate atoms, create molecules, and solve challenges such as protecting nature on a fictional planet under various physical threats.
De Florian told Physics Magazine about his experience developing this unconventional educational tool.
Researchers in the US and Germany have unveiled a theoretical blueprint for an atomic clock driven by a highly synchronized laser, where atoms work in concert rather than independently. Publishing their results in Physical Review Letters, Jarrod Reilly at the University of Colorado, Simon Jäger at the University of Bonn, and their colleagues in the US and Germany revived an idea first proposed in the 1990s—possibly charting a course toward the narrowest-linewidth lasers ever achieved.
In a conventional laser, a mirrored cavity bounces light back and forth between atoms, building up a bright, coherent beam. A superradiant laser works differently: rather than relying on the cavity to maintain coherence, the atoms themselves act as single coordinated emitters, collectively synchronizing their light emission.
Following early theoretical ideas emerged in the 1990s, the concept didn’t gain concrete traction until 2008, when researchers at the University of Colorado proposed that superradiant lasers could serve as a new kind of atomic clock.
Excitons are being explored in materials science and information technology as a means of storing light. These luminous quasiparticles move through individual layers of quantum materials and can absorb and emit light with high efficiency. They form when a laser pulse excites an electron, leaving behind a positively charged “hole.” The electron and hole attract each other and behave together like a new, independent particle. When the quasiparticle recombines, it emits light and can be detected in high-tech laboratories.
Excitons in ultrathin quantum materials have been intensively studied for more than a decade, including by Alexey Chernikov and his team. At the Cluster of Excellence ctd.qmat—Complexity, Topology and Dynamics in Quantum Matter—at the Universities of Würzburg and Dresden, Chernikov and an international research team based in Dresden have now made a surprising discovery: excitons can be carried along by the magnetic excitations of a quantum material and, as a result, accelerated to ultrahigh speeds. The findings are published in the journal Nature Nanotechnology.
“The fact that the motion of optical particles can be controlled by magnetism is new. Until now, we only knew that the transport of electrons could be controlled by the magnetic order in a quantum material—this is how some sensors in smartphones work, for example. This newly discovered link between optics and magnetism could open up entirely new technological possibilities,” explains Florian Dirnberger, head of an Emmy Noether Junior Research Group at the Technical University of Munich and formerly a postdoctoral researcher in Alexey Chernikov’s Chair of Ultrafast Microscopy and Photonics, where he was responsible for carrying out the research project.
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REFERENCES How black holes may be responsible for Dark Energy • How BLACK HOLES May be Responsible for DAR… Is Dark Energy made of particles? • Is Dark ENERGY made of PARTICLES? The Quin… What is Dark Energy made of? • What is Dark Energy made of? Quintessence?… CHAPTERS 0:00 The 70% mystery 0:58 How Dark Energy was discovered? 4:26 What could be causing Dark Energy? 6:58 Repulsive Gravity? 10:16 What is the energy made of? 11:56 Evolving Dark energy? Quintesssence 14:18 Could Dark Energy be a particle? 16:43 Could Black Holes cause Dark Energy? SUMMARY Dark energy is one of the greatest mysteries in modern physics. It appears to make up nearly 70% of the universe, yet scientists still do not know what it is. Unlike matter, it does not clump together. Unlike radiation, it does not dilute as space expands. Instead, it causes the expansion of the universe to accelerate, pushing galaxies apart faster over time. The discovery of this acceleration came in the late 1990s when astronomers measured distant Type Ia supernovae, which act as reliable “standard candles.” By comparing their brightness and redshift, researchers could determine how fast the universe expanded at different points in cosmic history. Instead of finding that gravity slowed expansion—as expected—they discovered the opposite: the universe was expanding faster and faster. This unexpected result led to the concept of dark energy, the unknown driver behind cosmic acceleration. One possible explanation is that dark energy is a cosmological constant, represented by the Greek letter lambda in Einstein’s equations. In this model, empty space itself contains a constant energy density known as vacuum energy. Quantum mechanics predicts that empty space is not truly empty; quantum fields constantly fluctuate, producing short-lived “virtual particles.” These fluctuations create energy even in a vacuum. Experiments like the Casimir effect provide evidence that vacuum energy is real. However, this explanation has a major problem. When physicists calculate vacuum energy using quantum theory, the predicted value is about 10¹²⁰ times larger than what observations of the universe allow. This enormous mismatch is widely considered the worst prediction in physics. In general relativity, cosmic acceleration can occur if the universe contains energy with negative pressure. In the Friedmann equation, expansion accelerates when pressure is sufficiently negative relative to energy density. Dark energy appears to have exactly this property, effectively producing a form of repulsive gravity that stretches spacetime. Another possibility is that dark energy is not constant but comes from a dynamic field known as quintessence. In quantum theory, fields can have particle-like excitations, meaning dark energy might correspond to extremely weakly interacting particles. If the strength of this field changes over time, the acceleration of the universe could grow stronger. In extreme scenarios, this could eventually lead to a catastrophic future known as the Big Rip, where galaxies, stars, atoms, and even spacetime itself are torn apart. A more speculative idea suggests a connection between supermassive black holes and dark energy. Some recent studies have observed that black holes appear to grow more massive over billions of years than expected from normal matter accretion alone. Researchers have proposed that black holes might somehow be linked to dark energy, though current evidence only shows a correlation and not a confirmed causal explanation. #darkenergy For now, dark energy remains an observed phenomenon with multiple possible explanations. Whether it is a property of empty space, a new field of physics, or something even deeper, it stands as one of the most profound open questions in cosmology.
CHAPTERS 0:00 The 70% mystery 0:58 How Dark Energy was discovered? 4:26 What could be causing Dark Energy? 6:58 Repulsive Gravity? 10:16 What is the energy made of? 11:56 Evolving Dark energy? Quintesssence 14:18 Could Dark Energy be a particle? 16:43 Could Black Holes cause Dark Energy?
SUMMARY Dark energy is one of the greatest mysteries in modern physics. It appears to make up nearly 70% of the universe, yet scientists still do not know what it is. Unlike matter, it does not clump together. Unlike radiation, it does not dilute as space expands. Instead, it causes the expansion of the universe to accelerate, pushing galaxies apart faster over time.
The discovery of this acceleration came in the late 1990s when astronomers measured distant Type Ia supernovae, which act as reliable “standard candles.” By comparing their brightness and redshift, researchers could determine how fast the universe expanded at different points in cosmic history. Instead of finding that gravity slowed expansion—as expected—they discovered the opposite: the universe was expanding faster and faster. This unexpected result led to the concept of dark energy, the unknown driver behind cosmic acceleration.
One possible explanation is that dark energy is a cosmological constant, represented by the Greek letter lambda in Einstein’s equations. In this model, empty space itself contains a constant energy density known as vacuum energy. Quantum mechanics predicts that empty space is not truly empty; quantum fields constantly fluctuate, producing short-lived “virtual particles.” These fluctuations create energy even in a vacuum. Experiments like the Casimir effect provide evidence that vacuum energy is real.
