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Archive for the ‘particle physics’ category: Page 31

Jul 24, 2024

Combining trapped atoms and photonics for new quantum devices

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

Quantum information systems offer faster, more powerful computing methods than standard computers to help solve many of the world’s toughest problems. Yet fulfilling this ultimate promise will require bigger and more interconnected quantum computers than scientists have yet built. Scaling quantum systems up to larger sizes, and connecting multiple systems, has proved challenging.

Jul 23, 2024

Twisted Graphene Could Host an Acoustic Plasmon

Posted by in categories: particle physics, quantum physics

Twisting the graphene sheets in a bilayer stack, so that the 2D orientations of the sheets are offset from one another, can drastically affect how the stack reacts to light. Researchers have observed the effect experimentally, but they lack an accurate theory of the behavior. Now Lorenzo Cavicchi at the Scuola Normale Superiore in Italy and collaborators have developed a theory that predicts that light-impinged twisted graphene bilayers could host two kinds of electron oscillations known as plasmons [1]. One of these plasmons, the acoustic plasmon, is tightly confined between the two graphene layers, giving it properties that could allow for its use in studying light–matter interactions.

The electrons in a twisted graphene bilayer are distributed unevenly across the system. This inhomogeneous distribution results from the system’s misaligned carbon atoms. Cavicchi and his colleagues accounted for the electron inhomogeneity in their theory. They also modeled the bilayer as two distinct sheets rather than as a single unit, as was done previously.

The team’s theory predicts the bilayer can host two kinds of plasmon oscillations: the previously known optical plasmon, where all electrons move in the same direction at the same time, and an acoustic plasmon, where the electrons in each sheet move in opposite directions. For a graphene bilayer with a 5° twist angle between the sheets, the researchers predict that the acoustic plasmon should have a velocity of about 840,000 meters per second. That velocity is slow enough that the oscillations are confined within the 0.3-nm gap between the graphene sheets. The researchers say that this tight confinement leads to interactions between the plasmon and incoming light that enhance the intensity of that incoming light. This behavior could be useful for applications in quantum cavities.

Jul 23, 2024

High-energy collision study reveals new insights into quark-gluon plasma

Posted by in categories: cosmology, particle physics

In high-energy physics, researchers have unveiled how high-energy partons lose energy in nucleus-nucleus collisions, an essential process in studying quark-gluon plasma (QGP). This finding could enhance our knowledge of the early universe moments after the Big Bang.

Jul 23, 2024

When Particles Outrun Light: Unraveling the Mystery of Cherenkov Radiation

Posted by in category: particle physics

New research explores the Cherenkov effect where superluminal speeds generate radiation and discusses new research using this principle to create terahertz radiation for advanced imaging and radar applications.

When charged particles travel through a medium at a speed greater than the phase speed of light in that medium (a phenomenon known as superluminal speed), they emit radiation. The resulting radiation forms a conical pattern. This phenomenon, known as the Cherenkov effect, has numerous fundamental and practical applications. The explanation of this effect earned the Nobel Prize in Physics in 1958.

The oblique incidence of light on the interface between two media is a similar phenomenon; in this case, a wave of secondary radiation sources is formed along the interface, which propagates at a speed exceeding the phase speed of light. The refraction and reflection of light from an interface is the result of the addition of the amplitudes of waves from all sources formed during light incidence.

Jul 23, 2024

Creating loops of liquid lithium for fusion temperature control

Posted by in categories: engineering, nuclear energy, particle physics

Fusion vessels have a Goldilocks problem: The plasma within needs to be hot enough to generate net power, but if it’s too hot, it can damage the vessel’s interior. Researchers at the Princeton Plasma Physics Laboratory (PPPL) are exploring ways to draw away excess heat, including several methods that use liquid metal.

One possibility, say researchers at the U.S. Department of Energy Lab, involves flowing liquid up and down a series of slats in tiles lining the bottom of the vessel. The liquid metal could also help to protect the components that face the against a bombardment of particles known as neutrons.

“The prevailing option for an economical commercial fusion reactor is a compact design,” said PPPL’s Egemen Kolemen, co-author of a 2022 paper on the research and an associate professor of mechanical and aerospace engineering and the Andlinger Center for Energy and the Environment. However, compactness makes handling the and neutron bombardment a bigger challenge.

Jul 23, 2024

Neil deGrasse Tyson and Sean Carroll Discuss Controversies in Quantum Mechanics

Posted by in categories: cosmology, internet, neuroscience, particle physics, quantum physics

What is the nature of quantum physics? Neil deGrasse Tyson and comedian Chuck Nice get quantum, exploring Schrodinger’s Cat, electrons, Hilbert Space, and the biggest ideas in the universe (in the smallest particles) with theoretical physicist Sean Carroll.

When did the idea of fields originate? Are fields even real or are they just mathematically convenient? We explore electrons, whether they are a field, and whether they exist at all. We also discuss the wave function, Hilbert Space, and what quantum mechanics really is. Do superpositions always exist?

Continue reading “Neil deGrasse Tyson and Sean Carroll Discuss Controversies in Quantum Mechanics” »

Jul 23, 2024

Astrophysicists uncover supermassive black hole/dark matter connection in solving the ‘final parsec problem’

Posted by in categories: cosmology, particle physics

Dark matter could bring black holes together.

Dark matter that interacts with itself could extract significant momentum from a binary supermassive black hole system, causing the black holes to merge.

A gravitational-wave “hum” pervades the Universe.

Continue reading “Astrophysicists uncover supermassive black hole/dark matter connection in solving the ‘final parsec problem’” »

Jul 23, 2024

The Higgs Boson Might Not Be The Portal to New Physics After All

Posted by in category: particle physics

They called it the God particle – a particle so ’goddamn’ elusive, it took nearly 40 years and a $4.75 billion machine to detect, all in the hopes of closing one chapter in physics and opening a new one.

Yet for all its promise, it’s possible the Higgs boson might not be the window to a new age of science.

On including previously neglected corrections to data-driven models of the Higgs boson’s creation, physicists from the Polish Academy of Sciences, the Max-Planck Institute for Physics, and the RWTH Aachen University in Germany have failed to find evidence of ‘hidden’ laws lurking in the particle’s shadow.

Jul 22, 2024

Scientists discover energy and pressure analogies linking hadrons, superconductors and cosmic expansion

Posted by in categories: particle physics, quantum physics

Quantum chromodynamics (QCD) is the theoretical framework for studying the forces within atomic nuclei and their constituent protons and neutrons. A major part of QCD research involves how quarks and gluons are contained within nucleons (protons and neutrons).

Jul 21, 2024

Machine learning unlocks secrets to advanced alloys

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

The concept of short-range order (SRO)—the arrangement of atoms over small distances—in metallic alloys has been underexplored in materials science and engineering. But the past decade has seen renewed interest in quantifying it, since decoding SRO is a crucial step toward developing tailored high-performing alloys, such as stronger or heat-resistant materials.

Understanding how atoms arrange themselves is no easy task and must be verified using intensive lab experiments or based on imperfect models. These hurdles have made it difficult to fully explore SRO in .

But Killian Sheriff and Yifan Cao, graduate students in MIT’s Department of Materials Science and Engineering (DMSE), are using to quantify, atom by atom, the complex chemical arrangements that make up SRO. Under the supervision of Assistant Professor Rodrigo Freitas, and with the help of Assistant Professor Tess Smidt in the Department of Electrical Engineering and Computer Science, their work was recently published in Proceedings of the National Academy of Sciences.

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