Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: particle physics

Quantum-dot device can generate multiple frequency-entangled photons

Researchers have designed a new device that can efficiently create multiple frequency-entangled photons, a feat that cannot be achieved with today’s optical devices. The new approach could open a path to more powerful quantum communication and computing technologies.

“Entangling particles efficiently is a critical capability for unlocking the full power of quantum technologies—whether to accelerate computations, surpass fundamental limits in precision measurement, or guarantee unbreakable security using the laws of quantum physics,” said Nicolas Fabre from Telecom Paris at the Institut Polytechnique de Paris.

“Photons are ideal because they can travel long distances through optical fibers or free space; however, there hasn’t been a way to efficiently generate frequency entanglement between more than two photons.”

New global standard set for testing graphene’s single-atom thickness

Graphene could transform everything from electric cars to smartphones, but only if we can guarantee its quality. The University of Manchester has led the world’s largest study to set a new global benchmark for testing graphene’s single-atom thickness. Working with the UK’s National Physical Laboratory (NPL) and 15 leading research institutes worldwide, the team has developed a reliable method using transmission electron microscopy (TEM) that will underpin future industrial standards.

Researchers at the University of Manchester, working with the UK’s National Physical Laboratory and 15 international partners, have developed a robust protocol using transmission electron microscopy (TEM). The results, published in 2D Materials, will underpin a new ISO technical specification for graphene.

“To incorporate graphene and other 2D materials into industrial applications, from light-weight vehicles to sports equipment, touch screens, sensors and electronics, you need to know you’re working with the right material. This study sets a global benchmark that industry can trust,” said Dr. William Thornley, who worked on the research during his Ph.D.

Negative Energy ‘Ghosts’ Flashing in Space Could Reveal New Physics

A ‘boom’ of light that appears when a particle exceeds the speed of light set by a medium could, in other contexts, signal a kind of quantum instability that could trigger what’s known as vacuum decay.

If ever spotted in the emptiness of space, according to theoretical physicist Eugeny Babichev of the University of Paris-Saclay, the eerie blue glow of Cherenkov radiation could be interpreted as a manifestation of negative-energy ghost perturbations.

Why does it matter? Because our current theory of gravity is incomplete, and such a signal would offer rare insight into how spacetime behaves in regimes where existing theories break down, and potentially narrow the search for better models.

Ghost Particles Interacting With Dark Matter Could Solve a Huge Cosmic Mystery

A new investigation of the early Universe led by Poland’s National Centre for Nuclear Research has just found that there may be an interaction between two of the most elusive components of the cosmos.

By combining different kinds of observations, cosmologists have shown that what we see is more easily explained if neutrinos, aka ‘ghost particles’, weakly interact with dark matter.

With a vexing certainty of three sigma, the signal isn’t strong enough to be definitive, but is also too strong to be a mere hint or noise in the data.

Atom-thin, content-addressable memory enables edge AI applications

Recent advances in the field of artificial intelligence (AI) have opened new exciting possibilities for the rapid analysis of data, the sourcing of information and the generation of use-specific content. To run AI models, current hardware needs to continuously move data from internal memory components to processors, which is energy-intensive and can increase the time required to tackle specific tasks.

Over the past few years, engineers have been trying to develop new systems that could overcome this limitation, running AI algorithms more reliably and efficiently. One proposed solution is the development of in-memory computing systems.

Content-addressable memory (CAM) is one of the earliest in-memory computing hardware systems, where memory components search for stored data faster, comparing each stored entry simultaneously based on its content, but faces challenges for AI applications because of the fundamental limitation of silicon transistors.

A new valve for quantum matter: Steering chiral fermions by geometry alone

A collaboration between Stuart Parkin’s group at the Max Planck Institute of Microstructure Physics in Halle (Saale) and Claudia Felser’s group at the Max Planck Institute for Chemical Physics of Solids in Dresden has realized a fundamentally new way to control quantum particles in solids. Writing in Nature, the researchers report the experimental demonstration of a chiral fermionic valve—a device that spatially separates quantum particles of opposite chirality using quantum geometry alone, without magnetic fields or magnetic materials.

The work was driven by Anvesh Dixit, a Ph.D. student in Parkin’s group in Halle, and the first author of the study, who designed, fabricated, and measured the mesoscopic devices that made the discovery possible.

“This project was only possible because we could combine materials with exceptional topological quality and transport experiments at the mesoscopic quantum limit,” says Anvesh Dixit. “Seeing chiral fermions separate and interfere purely due to quantum geometry is truly exciting.”

Water’s enigmatic surface: X-ray snapshots reveal atoms and molecules at work

Water is all around us, yet its surface layer—home to chemical reactions that shape life on Earth—is surprisingly hard to study. Experiments at SLAC’s X-ray laser are bringing it into focus.

Two-thirds of Earth’s surface is covered in water, most of it in oceans so deep and vast that only one-fifth of their total volume has been explored. Surprisingly, though, the most accessible part of this watery realm—the water’s surface, exposed on wave tops, raindrops and ponds full of skittering water striders—is one of the hardest to get to know.

Just a few layers of atoms thick, the surface plays an outsized role in the chemistry that makes our world what it is—from the formation of clouds and the recycling of water through rainfall to the ocean’s absorption of carbon dioxide from the atmosphere.

NASA Balloon Detects Strange Signals Coming From Ice in Antarctica

Unusual radio signals from beneath Antarctica’s ice continue to defy explanation. Several years ago, scientists using a cosmic particle detector in Antarctica recorded a series of puzzling radio signals, according to an international research collaboration that includes experts from Penn State. Bet

Tetraquark measurements could shed more light on the strong nuclear force

Identifying and studying tetraquarks and pentaquarks helps physicists to better understand how the strong force binds quarks together. This force also binds protons and neutrons in atomic nuclei.

Physicists are still divided as to the nature of these exotic hadrons. Some models suggest that their quarks are tightly bound via the strong force, so making these hadrons compact objects. Others say that the quarks are only loosely bound. To confuse things further, there is evidence that in some exotic hadrons, the quarks might be both tightly and loosely bound at the same time.

Now, new findings from the CMS Collaboration suggest that tetraquarks are tightly bound, but they do not completely rule out other models.

Elusive Quantum Interactions Tracked During Cooling

Over the past few decades, researchers have used ultracold atomic gases to simulate high-temperature superconductors and other materials in which electrons interact strongly. Frustratingly, these experiments have failed to uncover the temperature dependence of certain “p-wave” interactions relevant to some superconductors and superfluids. Now Kenta Nagase and his colleagues at the Institute of Science Tokyo have tracked how these interactions change as a cloud of lithium atoms is cooled toward absolute zero [1]. The results could help scientists better understand the behavior of certain exotic superconductors.

In a p-wave interaction, particles collide with each other in such a way that their interaction strength depends on their relative orientations. The inherent complexity of these interactions, such as their occurrence through three different scattering channels, meant that their predicted temperature dependence lacked experimental confirmation. To surmount this hurdle, Nagase and his colleagues isolated and analyzed the contributions to the interactions from each channel. They repeated their experiment at many temperatures, controlled by the strength of the optical trap confining the lithium cloud.

As they cooled the lithium cloud, Nagase and his colleagues saw that the strength of p-wave interactions increased, in agreement with predictions. These interactions caused the lithium atoms to briefly form fragile molecules, mimicking the pairing of electrons in a superconductor. The measured number, angular distribution, and behavior of such molecules were also consistent with expectations. These properties had been explored in the lab only partially, so the new work provides stronger support for current models of ultracold atomic gases.

/* */