Physicists show that neutron stars may be shrouded in clouds of ‘axions’ — and that these clouds can teach us a lot. A team of physicists from the universities of Amsterdam, Princeton and Oxford have shown that extremely light particles known as axions may occur in large clouds around neutron stars. These axions could form an explanation for the elusive dark matter that cosmologists search for — and moreover, they might not be too difficult to observe.
The Large Hadron Collider (LHC) is like an immensely powerful kitchen, designed to cook up some of the rarest and hottest recipes in the universe, like the quark–gluon plasma, a state of matter known to have existed shortly after the Big Bang. While the LHC mostly collides protons, once a year it collides heavy ions—such as lead nuclei—a key ingredient for preparing this primordial soup.
An experimental setup built at the Technion Faculty of Physics demonstrates the transfer of atoms from one place to another through quantum tunneling between optical tweezers. Led by Prof. Yoav Sagi and doctoral student Yanay Florshaim from the Solid State Institute, the research was published in Science Advances.
A group of scientists from Skoltech, led by Skoltech Vice President for Photonics Pavlos Lagoudakis, a laureate of the Vyzov (Challenge) prize, shared new results of the polariton condensate research. The team demonstrated that under optical excitation a polariton condensate can simultaneously occupy two closely spaced energy levels, which results in the formation of quantized vortex clusters. The outcomes of the study are prominent for optical tweezers, increasing the width of the data transmission channel in optical communication lines, and in other research areas. The paper was published in the Applied Physics Letters journal. It was featured on the cover of the weekly issue.
The new study is based on the previous work on optical vortices — optical beams that have their phase twisted in a spiral around the propagation axis. In 2022, Skoltech researchers, together with their colleagues from the University of Iceland and the University of Southampton, were the first to show how a cluster of quantized vortices with periodically flipping charges is formed in polariton condensates. The authors experimentally observed a cluster of four vortices and detected periodic flips of the signs of their charges with an interval of one fifth of a nanosecond.
“Polaritons are quasi-particles consisting of light and matter. They can form a macroscopic coherent state — Bose-Einstein condensate. This state behaves, roughly speaking, like one particle and is described by a single wave function. But the condensation of polaritons in inorganic microresonators is achieved not at room temperature, but at extremely low ones, therefore, to observe the condensation of polaritons, we place the sample in which they appear in a cryostat, where it is cooled to four degrees Kelvin,” says Kirill Sitnik, the first author of the study, a junior research scientist at the Skoltech Photonics Center’s Laboratory of Hybrid Photonics.
For the first time, researchers have observed how bromoform rearranges its atoms in less than a trillionth of a second after it gets hit by an ultraviolet (UV) pulse. The imaging technique captured a long-predicted pathway by which the ozone-layer-damaging molecule transforms its structure upon interaction with light.
Fermilab is tackling the extreme conditions generated in neutrino experiments to ensure the success of future research.
“Researchers need to overcome three challenges to make a lasting target: radiation damage, high temperatures and stress from thermal expansion,” remarked the press release.
Nanofibers, incredibly thin threads with exceptional strength and flexibility, are being investigated for their ability to better absorb the shock of the proton beam.
“A nanofiber developed by Fermilab engineer Sujit Bidhar is being researched as a potential target material due to its ability to mitigate thermal shock and be more resistant to radiation damage,” highlighted the press release.
Earlier this year, experiments shattered expectations by pushing the limits of what classical computing was believed to be capable of. Not only did the old fashioned binary technology crack a problem considered to be unique to quantum processing, it outperformed it.
Now physicists from the Flatiron Institute’s Center for Computational Quantum Physics in the US have an explanation for the feat which could help better define the boundaries between the two radically different methods of number-crunching.
The problem involves simulating the dynamics of what’s known as a transverse field Ising (TFI) model, which describes the alignment of quantum spin states between particles spread across a space.
Scientists at Brookhaven National Laboratory have used supercomputer simulations to predict electric charge distributions in mesons, essential for understanding the subatomic structure of matter.
Upcoming experiments at the Electron-Ion Collider (EIC) will further validate these predictions, offering new insights into how quarks and gluons interact to form visible matter.
Exploring Meson Charge Distribution