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Archive for the ‘particle physics’ category: Page 92

Mar 9, 2024

What is the big rip, and can we stop it?

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

If two points were ripped apart faster than light, they would no longer interact through any force of physics. Whereas a constant dark energy would leave behind already-intact objects, like clusters of galaxies, phantom energy could tear them apart. In a finite amount of time, billions of years from now, clusters would tear apart, followed by ever-smaller objects. Even atomic and nuclear bonds would not withstand the onslaught.

Eventually, space itself would dissolve in an event known as the Big Rip. Any two points, no matter how close, would be ripped infinitely far away from each other. The very structure of space-time, the causal foundations that make our universe work, would no longer behave. The universe would just break down.

However, luckily, most physicists do not believe this scenario can actually happen. For one, it’s unclear how this process of ripping interacts with the other laws of physics. For example, quarks cannot be torn apart — when you attempt to do so, you need so much energy that new quarks materialize out of the vacuum. So ripping apart quarks just might lead to other, interesting interactions.

Mar 9, 2024

Exploring the surface properties of NiO with low-energy electron diffraction

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

Spintronics is a field that deals with electronics that exploit the intrinsic spin of electrons and their associated magnetic moment for applications such as quantum computing and memory storage devices. Owing to its spin and magnetism exhibited in its insulator-metal phase transition, the strongly correlated electron systems of nickel oxide (NiO) have been thoroughly explored for more than eight decades. Interest in its unique antiferromagnetic (AF) and spin properties has seen a revival lately since NiO is a potential material for ultrafast spintronics devices.

Despite this rise in popularity, exploration of its magnetic properties using the low-energy electron diffraction (LEED) technique has not received much attention since the 1970s. To review the understanding of the surface properties, Professor Masamitsu Hoshino and Emeritus Professor Hiroshi Tanaka, both from the Department of Physics at Sophia University, Japan, revisited the surface LEED crystallography of NiO.

The results of their quantitative experimental study investigating the coherent exchange scattering in Ni2+ ions in AF single crystal NiO were reported in The European Physical Journal D.

Mar 9, 2024

We May Finally Know How The First Cells on Earth Formed

Posted by in categories: chemistry, particle physics

The story of how life started on Earth is one that scientists are eager to learn. Researchers may have uncovered an important detail in the plot of chapter one: an explanation of how bubbles of fat came to form the membranes of the very first cells.

A key part of the new findings, made by a team from The Scripps Research Institute in California, is that a chemical process called phosphorylation may have happened earlier than previously thought.

Continue reading “We May Finally Know How The First Cells on Earth Formed” »

Mar 9, 2024

Physicists Reveal a Strange Form of Crystal Where Electrons Can’t Move

Posted by in categories: particle physics, quantum physics

Quantum traffic laws applied to the 3D streetscape of a specific kind of crystal can put the brakes on electron rush hour.

In a search for novel materials that can contain bizarre new states of matter, physicists from Rice University in the US led an experiment that forced free-roaming electrons to stay in place.

While the phenomenon has been seen in materials where electrons are constrained to just two dimensions, this is the first time it’s been observed in a three-dimensional crystal metal lattice, known as a pyrochlore. The technique gives researchers a new tool for studying the less conventional activities of plucky, charge-carrying particles.

Mar 8, 2024

Optically trapped quantum droplets of light can bind together to form macroscopic complexes

Posted by in categories: particle physics, quantum physics

Condensed matter systems and photonic technologies are regularly used by researchers to create microscale platforms that can simulate the complex dynamics of many interacting quantum particles in a more accessible setting. Some examples include ultracold atomic ensembles in optical lattices, superconducting arrays, and photonic crystals and waveguides. In 2006 a new platform emerged with the demonstration of macroscopically coherent quantum fluids of exciton-polaritons to explore many-body quantum phenomena through optical techniques.

When a piece semiconductor is placed between two mirrors—an optical microresonator—the electronic excitations within can become strongly influenced by photons trapped between the mirrors. The resulting new bosonic , known as exciton-polaritons (or polaritons for short), can under the right circumstances undergo a phase transition into a nonequilibrium Bose-Einstein condensate and form a macroscopic quantum fluid or a droplet of light.

Quantum fluids of polaritons have many salient properties, one being that they are optically configurable and readable, permitting easy measurements of the dynamics. This is what makes them so advantageous to simulate many-body physics.

Mar 8, 2024

Open quantum system shows universal behavior

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

Universal behavior is a central property of phase transitions, which can be seen, for example, in magnets that are no longer magnetic above a certain temperature. A team of researchers from Kaiserslautern, Berlin and Hainan, China, has succeeded for the first time in observing such universal behavior in the temporal development of an open quantum system, a single cesium atom in a bath of rubidium atoms.

This finding helps to understand how quantum systems reach equilibrium. This is of interest to the development of quantum technologies, for example. The study has been published in Nature Communications.

Phase transitions in chemistry and physics are changes in the state of a substance, for example, the change from a liquid to a gaseous phase, when an external parameter such as temperature or pressure is changed.

Mar 8, 2024

Aluminum nanoparticles make tunable green catalysts

Posted by in categories: chemistry, nanotechnology, particle physics, sustainability

Catalysts unlock pathways for chemical reactions to unfold at faster and more efficient rates, and the development of new catalytic technologies is a critical part of the green energy transition.

The Rice University lab of nanotechnology pioneer Naomi Halas has uncovered a transformative approach to harnessing the catalytic power of aluminum nanoparticles by annealing them in various gas atmospheres at high temperatures.

According to a study published in the Proceedings of the National Academy of Sciences, Rice researchers and collaborators showed that changing the structure of the oxide layer that coats the particles modifies their , making them a versatile tool that can be tailored to suit the needs of different contexts of use from the production of sustainable fuels to water-based reactions.

Mar 7, 2024

Plasma oscillations propel breakthroughs in fusion energy

Posted by in categories: nuclear energy, particle physics

Most people know about solids, liquids, and gases as the main three states of matter, but a fourth state of matter exists as well. Plasma—also known as ionized gas—is the most abundant, observable form of matter in our universe, found in the sun and other celestial bodies.

Creating the hot mix of freely moving electrons and ions that compose a often requires extreme pressures or temperatures. In these , researchers continue to uncover the unexpected ways that plasma can move and evolve. By better understanding the motion of plasma, scientists gain valuable insights into solar physics, astrophysics, and fusion.

In a paper published in Physical Review Letters, researchers from the University of Rochester, along with colleagues at the University of California, San Diego, discovered a new class of plasma oscillations—the back-and-forth, wave-like movement of electrons and ions. The findings have implications for improving the performance of miniature particle accelerators and the reactors used to create fusion energy.

Mar 7, 2024

Giant leap toward neuromorphic devices: High-performance spin-wave reservoir computing

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

A group of Tohoku University researchers has developed a theoretical model for a high-performance spin wave reservoir computing (RC) that utilizes spintronics technology. The breakthrough moves scientists closer to realizing energy-efficient, nanoscale computing with unparalleled computational power.

Details of their findings were published in npj Spintronics on March 1, 2024.

The brain is the ultimate computer, and scientists are constantly striving to create neuromorphic devices that mimic the brain’s processing capabilities, , and its ability to adapt to neural networks. The development of neuromorphic computing is revolutionary, allowing scientists to explore nanoscale realms, GHz speed, with low energy consumption.

Mar 3, 2024

Synergy palladium single atoms and twinned nanoparticles for efficient CO₂ photoreduction

Posted by in categories: engineering, nanotechnology, particle physics

The challenge of regulating the electronic structures of metal single-atoms (M-SAs) with metal nanoparticles (M-NPs) lies in the synthesis of a definite architecture. Such a structure has strong electronic metal-support interactions and maintains electron transport channels to facilitate carbon dioxide photoreduction (CO2PR).

In a study published in Advanced Powder Materials, a group of researchers from Zhejiang Normal University, Zhejiang A&F University and Dalian University of Technology, revealed the engineering of the of Pd single atoms with twinned Pd nanoparticles assisted by strong electronic interaction of the atomic metal with the support and unveiled the underlying mechanism for expedited CO2PR.

“As one of the most promising CO2PR semiconductors, polymeric graphitic carbon nitride (g-C3N4) featured with sp2 π-conjugated lamellar structures can offer electronegative nitrogen atoms to anchor M-SAs, forming active metal-nitrogen moieties (M–Nx),” explained Lei Li, lead author of the study. “However, stable M–Nx configurations forbid tunability of electronic structures of M-SA sites.”

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