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Archive for the ‘particle physics’ category: Page 332

Dec 25, 2020

MIT’s quantum entangled atomic clock could still be ticking after billions of years

Posted by in categories: particle physics, quantum physics

Famous medieval poet and author Geoffrey Chaucer once wrote that “‘time and tide wait for no man,” and that certainly rings true whether you’ve still got a ’90s Swatch watch strapped to your wrist, your name is Doc Brown, or you’re a brilliant scientist working on the latest atomic clock design — which employs lasers to trap and measure oscillations of quantum entangled atoms to maintain precise timekeeping.

The official time for the United States is set at the atomic clock located at the National Institute of Standards and Technology in Boulder, Colorado, where this Cesium Fountain Atomic Clock remains accurate to within one second every 300 million years. Its cesium-133 atom vibrates exactly 9, 192, 631, 770 times per second, a permanent statistic that has officially measured one second since the machine’s inception and operational rollout back in 1968.

Dec 25, 2020

Making jet fuel out of carbon dioxide

Posted by in categories: business, chemistry, particle physics, sustainability, transportation

A team of researchers affiliated with several institutions in the U.K. and one in Saudi Arabia has developed a way to produce jet fuel using carbon dioxide as a main ingredient. In their paper published in the journal Nature Communications, the group describes their process and its efficiency.

As scientists continue to look for ways to reduce the amount of emitted into the atmosphere, they have increasingly focused on certain business sectors. One of those sectors is the , which accounts for approximately 12% of transportation-related carbon dioxide emissions. Curbing in the aviation industry has proved to be challenging due to the difficulty of fitting heavy batteries inside of aircraft. In this new effort, the researchers have developed a that can be used to produce carbon-neutral jet fuel.

The researchers used a process called the organic combustion method to convert carbon dioxide in the air into jet fuel and other products. It involved using an iron catalyst (with added potassium and manganese) along with hydrogen, citric acid and carbon dioxide heated to 350 degrees C. The process forced the apart from the oxygen atoms in CO2 molecules, which then bonded with hydrogen atoms, producing the kind of hydrocarbon molecules that comprise liquid jet fuel. The process also resulted in the creation of water molecules and other products.

Dec 25, 2020

Jack Steinberger (1921–2020)

Posted by in category: particle physics

Particle physicist who shared Nobel for discovering muon neutrinos.

Dec 24, 2020

Beam me up: long-distance quantum teleportation has happened for the first time ever

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

Raise your hand if you ever wanted to get beamed onto the transport deck of the USS Enterprise. Maybe we haven’t reached the point of teleporting entire human beings yet (sorry Scotty), but what we have achieved is a huge breakthrough towards quantum internet.

Led by Caltech, a collaborative team from Fermilab, NASA’s Jet Propulsion Lab, Harvard University, the University of Calgary and AT&T have now successfully teleported qubits (basic units of quantum info) across almost 14 miles of fiber optic cables with 90 percent precision. This is because of quantum entanglement, the phenomenon in which quantum particles which are mysteriously “entangled” behave exactly the same even when far away from each other.

Dec 24, 2020

Atomic-scale nanowires can now be produced at scale

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

Researchers from Tokyo Metropolitan University have discovered a way to make self-assembled nanowires of transition metal chalcogenides at scale using chemical vapor deposition. By changing the substrate where the wires form, they can tune how these wires are arranged, from aligned configurations of atomically thin sheets to random networks of bundles. This paves the way to industrial deployment in next-gen industrial electronics, including energy harvesting, and transparent, efficient, even flexible devices.

Electronics is all about making things smaller—smaller features on a chip, for example, means more computing power in the same amount of space and better efficiency, essential to feeding the increasingly heavy demands of a modern IT infrastructure powered by machine learning and artificial intelligence. And as devices get smaller, the same demands are made of the intricate wiring that ties everything together. The ultimate goal would be a wire that is only an atom or two in thickness. Such would begin to leverage completely different physics as the electrons that travel through them behave more and more as if they live in a one-dimensional world, not a 3D one.

In fact, scientists already have materials like carbon nanotubes and transition metal chalcogenides (TMCs), mixtures of transition metals and group 16 elements which can self-assemble into atomic-scale nanowires. The trouble is making them long enough, and at scale. A way to mass produce nanowires would be a game changer.

Dec 23, 2020

Experiment takes ‘snapshots’ of light, stops light, uses light to change properties of matter

Posted by in category: particle physics

Light travels at a speed of about 300, 000, 000 meters per second as light particles, photons, or equivalently as electromagnetic field waves. Experiments led by Hrvoje Petek, an R.K. Mellon professor in the Department of Physics and Astronomy examined ideas surrounding the origins of light, taking snapshots of light, stopping light and using it to change properties of matter.

Petek worked with students and collaborators Prof. Chen-Bin (Robin) Huang of the National Tsing Hua University in Taiwan, and Atsushi Kubo of the Tsukuba University of Japan on the experiments. Their findings were reported in the paper, “Plasmonic topological quasiparticle on the nanometre and femtosecond scales,” which was published in the Dec. 24 issue of Nature magazine.

Petek credited graduate student Yanan Dai for his foresight and work in the process.

Dec 22, 2020

New Material System Developed to Convert and Generate Terahertz Waves for Tomorrow’s Technologies

Posted by in categories: internet, nanotechnology, particle physics

On the electromagnetic spectrum, terahertz light is located between infrared radiation and microwaves. It holds enormous potential for tomorrow’s technologies: Among other things, it might succeed 5G by enabling extremely fast mobile communications connections and wireless networks. The bottleneck in the transition from gigahertz to terahertz frequencies has been caused by insufficiently efficient sources and converters. A German-Spanish research team with the participation of the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) has now developed a material system to generate terahertz pulses much more effectively than before. It is based on graphene, i.e., a super-thin carbon sheet, coated with a metallic lamellar structure. The research group presented its results in the journal ACS Nano.

Some time ago, a team of experts working on the HZDR accelerator ELBE were able to show that graphene can act as a frequency multiplier: When the two-dimensional carbon is irradiated with light pulses in the low terahertz frequency range, these are converted to higher frequencies. Until now, the problem has been that extremely strong input signals, which in turn could only be produced by a full-scale particle accelerator, were required to generate such terahertz pulses efficiently.“This is obviously impractical for future technical applications,” explains the study’s primary author Jan-Christoph Deinert of the Institute of Radiation Physics at HZDR. “So, we looked for a material system that also works with a much less violent input, i.e., with lower field strengths.”

For this purpose, HZDR scientists, together with colleagues from the Catalan Institute of Nanoscience and Nanotechnology (ICN2), the Institute of Photonic Sciences (ICFO), the University of Bielefeld, TU Berlin and the Mainz-based Max Planck Institute for Polymer Research, came up with a new idea: the frequency conversion could be enhanced enormously by coating the graphene with tiny gold lamellae, which possess a fascinating property: “They act like antennas that significantly amplify the incoming terahertz radiation in graphene,” explains project coordinator Klaas-Jan Tielrooij from ICN2. “As a result, we get very strong fields where the graphene is exposed between the lamellae. This allows us to generate terahertz pulses very efficiently.”

Dec 22, 2020

When light and atoms share a common vibe

Posted by in categories: particle physics, quantum physics

An especially counter-intuitive feature of quantum mechanics is that a single event can exist in a state of superposition—happening both here and there, or both today and tomorrow.

Such superpositions are hard to create, as they are destroyed if any kind of information about the place and time of the event leaks into the surrounding—and even if nobody actually records this information. But when superpositions do occur, they lead to observations that are very different from that of classical physics, raising questions that spill over into our very understanding of space and time.

Scientists from EPFL, MIT, and CEA Saclay, publishing in Science Advances, demonstrate a state of vibration that exists simultaneously at two different times, and provide evidence of this by measuring the strongest class of quantum correlations between that interact with the vibration.

Dec 21, 2020

Artificial intelligence solves Schrödinger’s equation

Posted by in categories: chemistry, information science, mathematics, particle physics, quantum physics, robotics/AI, space

A team of scientists at Freie Universität Berlin has developed an artificial intelligence (AI) method for calculating the ground state of the Schrödinger equation in quantum chemistry. The goal of quantum chemistry is to predict chemical and physical properties of molecules based solely on the arrangement of their atoms in space, avoiding the need for resource-intensive and time-consuming laboratory experiments. In principle, this can be achieved by solving the Schrödinger equation, but in practice this is extremely difficult.

Up to now, it has been impossible to find an exact solution for arbitrary molecules that can be efficiently computed. But the team at Freie Universität has developed a deep learning method that can achieve an unprecedented combination of accuracy and computational efficiency. AI has transformed many technological and scientific areas, from computer vision to materials science. “We believe that our approach may significantly impact the future of quantum ,” says Professor Frank Noé, who led the team effort. The results were published in the reputed journal Nature Chemistry.

Central to both quantum chemistry and the Schrödinger equation is the —a mathematical object that completely specifies the behavior of the electrons in a molecule. The wave function is a high-dimensional entity, and it is therefore extremely difficult to capture all the nuances that encode how the individual electrons affect each other. Many methods of quantum chemistry in fact give up on expressing the wave function altogether, instead attempting only to determine the energy of a given molecule. This however requires approximations to be made, limiting the prediction quality of such methods.

Dec 21, 2020

New nanomaterial helps obtain hydrogen from a liquid energy carrier, in a key step toward a stable and clean fuel source

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

Hydrogen is a sustainable source of clean energy that avoids toxic emissions and can add value to multiple sectors in the economy including transportation, power generation, metals manufacturing, among others. Technologies for storing and transporting hydrogen bridge the gap between sustainable energy production and fuel use, and therefore are an essential component of a viable hydrogen economy. But traditional means of storage and transportation are expensive and susceptible to contamination. As a result, researchers are searching for alternative techniques that are reliable, low-cost and simple. More-efficient hydrogen delivery systems would benefit many applications such as stationary power, portable power, and mobile vehicle industries.

Now, as reported in the journal Proceedings of the National Academy of Sciences, researchers have designed and synthesized an effective material for speeding up one of the limiting steps in extracting from alcohols. The material, a , is made from tiny clusters of nickel anchored on a 2-D substrate. The team led by researchers at Lawrence Berkeley National Laboratory’s (Berkeley Lab) Molecular Foundry found that the catalyst could cleanly and efficiently accelerate the reaction that removes hydrogen atoms from a liquid chemical carrier. The material is robust and made from earth-abundant metals rather than existing options made from precious metals, and will help make hydrogen a viable energy source for a wide range of applications.

“We present here not merely a catalyst with higher activity than other nickel catalysts that we tested, for an important renewable energy fuel, but also a broader strategy toward using affordable metals in a broad range of reactions,” said Jeff Urban, the Inorganic Nanostructures Facility director at the Molecular Foundry who led the work. The research is part of the Hydrogen Materials Advanced Research Consortium (HyMARC), a consortium funded by the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy Hydrogen and Fuel Cell Technologies Office (EERE). Through this effort, five national laboratories work towards the goal to address the scientific gaps blocking the advancement of solid hydrogen storage materials. Outputs from this work will directly feed into EERE’s H2@Scale vision for affordable hydrogen production, storage, distribution and utilization across multiple sectors in the economy.