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Archive for the ‘particle physics’ category: Page 238

Sep 27, 2022

Exotic electronic effect found in 2D topological material

Posted by in categories: particle physics, quantum physics, robotics/AI

Jülich researchers have been able to demonstrate an exotic electronic state, so-called Fermi Arcs, for the first time in a 2D material. The surprising appearance of Fermi arcs in such a material provides a link between novel quantum materials and their respective potential applications in a new generation of spintronics and quantum computing. The results have recently been published in Nature Communications.

The newly detected Fermi arcs represent special—arc-like—deviations from the so-called Fermi surface. The Fermi surface is used in condensed matter physics to describe the momentum distribution of electrons in a metal. Normally, these Fermi surfaces represent closed surfaces. Exceptions such as the Fermi arcs are very rare and often are associated with exotic properties like superconductivity, negative magnetoresistance and anomalous quantum transport effects.

Today’s technology challenge is to develop the “on-demand” control of physical properties in materials. However, such experimental tests have been largely limited to bulk materials and are key grand challenges in condensed matter science. With its groundbreaking paradigm, the findings present a promising new frontier for quantum control of topological states in low-dimensional systems by external means—the that offers unprecedented capabilities on 2D materials for as well as future information processing.

Sep 26, 2022

Team of physicists finds signs of pentaquark states and new matter

Posted by in category: particle physics

Theorists at the University of Pittsburgh and Swansea University have shown that recent experimental results from the CERN collider give strong evidence for a new form of matter.

The experiment at CERN, site of the world’s highest-energy particle collider, examined a heavy particle called a Lambda b that decays to lighter particles, including the familiar proton and the famed J/psi, discovered in 1974.

In a paper published online today in Physical Review D, physicists Tim Burns of Swansea in Wales and Eric Swanson at Pitt argue that the data can be understood only if a new type of matter exists.

Sep 26, 2022

Physicists shed light on a different kind of chaos

Posted by in categories: computing, particle physics, quantum physics

Physicists at UC Santa Barbara, the University of Maryland, and the University of Washington have found an answer to the longstanding physics question: How do interparticle interactions affect dynamical localization?

“It’s a really old question inherited from condensed matter physics,” said David Weld, an experimental physicist at UCSB with specialties in ultracold atomic physics and . The question falls into the category of “many-body” physics, which interrogates the physical properties of a quantum system with multiple interacting parts. While many-body problems have been a matter of research and debate for decades, the complexity of these systems, with quantum behaviors such as superposition and entanglement, lead to multitudes of possibilities, making it impossible to solve through calculation alone. “Many aspects of the problem are beyond the reach of modern computers,” Weld added.

Fortunately, this problem was not beyond the reach of an experiment that involves ultracold lithium atoms and lasers. So, what emerges when you introduce interaction in a disordered, chaotic quantum system? A “weird quantum state,” according to Weld. “It’s a state which is anomalous, with properties which in some sense lie between the classical prediction and the non-interacting quantum prediction.”

Sep 24, 2022

Physicists make molecular vibrations more detectable

Posted by in categories: chemistry, particle physics, quantum physics

In molecules, the atoms vibrate with characteristic patterns and frequencies. Vibrations are therefore an important tool for studying molecules and molecular processes such as chemical reactions. Although scanning tunneling microscopes can be used to image individual molecules, their vibrations have so far been difficult to detect.

Physicists at Kiel University (Christian-Albrechts-Universität zu Kiel, CAU) have now invented a method with which the vibration signals can be amplified by up to a factor of 50. Furthermore, they increased the frequency resolution considerably. The new method will improve the understanding of interactions in molecular systems and further simulation methods. The research team has now published the results in the journal Physical Review Letters.

Continue reading “Physicists make molecular vibrations more detectable” »

Sep 24, 2022

The Doomsday Explosive! (The Neutronium Bomb)

Posted by in categories: existential risks, particle physics

Neutronium was the material used in the hull of the doomsday machine in Star Trek.

Now I’m not terribly sure what the mechanical properties of neutronium would be like. It certainly is very dense (about a billion tons per cm3, about the volume of the end of your little finger), but it interacts with matter only weakly. I would expect both it to be pretty inefficient at stopping both electromagnetic radiation (neutrons only have a magnetic moment), and matter.

Continue reading “The Doomsday Explosive! (The Neutronium Bomb)” »

Sep 24, 2022

Science is on brink of a materials revolution

Posted by in categories: particle physics, science

Imagine a world where super-strong, super-light, flexible, durable new materials, which don’t exist in nature could be made to order. New breakthroughs in the understanding of “spin”, a characteristic of subatomic particles — like mass and charge — mean we are on the brink of such a revolution.

“The ability to control spin, one of the fundamental properties of particles, is crucial to us being able to design advanced new materials that will change the world,” says Prof Alessandro Lunghi, a physicist at Trinity College Dublin, who heads up a team investigating the phenomenon.

The scientific concepts of particle mass and charge are widely understood and known, but the third property of particles — that of spin — remains mysterious to most. It’s a concept that even many scientists struggle to understand.

Sep 24, 2022

Between two universes

Posted by in categories: computing, particle physics, quantum physics

When Mohammad Javad Khojasteh arrived at MIT’s Laboratory for Information and Decision Systems (LIDS) in 2020 to begin his postdoc appointment, he was introduced to an entirely new universe. The domain he knew best could be explained by “classical” physics that predicts the behavior of ordinary objects with near-perfect accuracy (think Newton’s three laws of motion). But this new universe was governed by bizarre laws that can produce unpredictable results while operating at scales typically smaller than an atom.

“The rules of quantum mechanics are counterintuitive and seem very strange when you first start to learn them,” Khojasteh says. “But the more you know, the clearer it becomes that the underlying logic is extremely elegant.”

As a member of Professor Moe Win’s lab, called the Wireless Information and Network Sciences Laboratory, or WINS Lab, Khojasteh’s job is to straddle both the classical and quantum realms, in order to improve state-of-the-art communication, sensing, and computational capabilities.

Sep 24, 2022

Marvin Minsky — Why is Consciousness so Mysterious?

Posted by in categories: neuroscience, particle physics

How can the mindless microscopic particles that compose our brains ‘experience’ the setting sun, the Mozart Requiem, and romantic love?

For all of our video interviews please visit us at www.closertotruth.com

Sep 23, 2022

Catching neutrinos at the LHC

Posted by in categories: particle physics, space

CERN physicist Jamie Boyd enters a tunnel close to the ATLAS detector, an experiment at the largest particle accelerator in the world. From there, he turns into an underground space labeled TI12.

“This is a very special tunnel,” Boyd says, “because this is where the old transfer line used to exist for the Large Electron-Positron Collider, before the Large Hadron Collider.” After the LHC was built, a new transfer line was added, “and this tunnel was then abandoned.”

The tunnel is abandoned no more. Its new resident is an experiment much humbler in size than the neighboring ATLAS detector. Five meters in length, the ForwArd Search ExpeRiment, or FASER, detector sits in a shallow excavated trench in the floor, surrounded by low railings and cables.

Sep 22, 2022

A Jiggling Ultracold Atomic Gas Simulates Spin Dynamics

Posted by in categories: particle physics, quantum physics

Researchers produce analogues of hard-to-study quantum phenomena in a gas of strontium atoms near absolute zero.

Recently, researchers have begun using ultracold atomic gases to simulate phenomena that are difficult to study in their natural environments. Using electromagnetic fields, for example, they can orchestrate interatomic interactions that are analogous to interactions in condensed-matter systems, which they can then study with greater experimental control than the real examples allow. Now David Wilkowski of Nanyang Technological University in Singapore and colleagues use an ultracold atomic gas to simulate a condensed-matter system’s spin dynamics [1].

Wilkowski’s team cools a gas of strontium-87 atoms to 30 nK. Then, using three convergent laser beams, they drive the gas through various transitions until the atoms populate two so-called dark states, in which quantum mechanics forbids the atoms from undergoing spontaneous emission.