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Archive for the ‘particle physics’ category: Page 556

Nov 25, 2015

‘Material universe’ yields surprising new particle

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

An international team of researchers has predicted the existence of a new type of particle called the type-II Weyl fermion in metallic materials. When subjected to a magnetic field, the materials containing the particle act as insulators for current applied in some directions and as conductors for current applied in other directions. This behavior suggests a range of potential applications, from low-energy devices to efficient transistors.

The researchers theorize that the particle exists in a material known as tungsten ditelluride (WTe2), which the researchers liken to a “material universe” because it contains several , some of which exist under normal conditions in our universe and others that may exist only in these specialized types of crystals. The research appeared in the journal Nature this week.

The new particle is a cousin of the Weyl fermion, one of the particles in standard theory. However, the type-II particle exhibits very different responses to electromagnetic fields, being a near perfect conductor in some directions of the field and an insulator in others.

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Nov 25, 2015

Physicists set quantum record

Posted by in categories: particle physics, quantum physics

Researchers from Stanford have advanced a long-standing problem in quantum physics – how to send “entangled” particles over long distances.

Their work is described in the online edition of Nature Communications.

Scientists and engineers are interested in the practical application of this technology to make networks that can send highly secure information over long distances – a capability that also makes the technology appealing to governments, banks and militaries.

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Nov 25, 2015

Stephen Hawking’s Legacy Could Be ‘Holy Grail’ Of Physics: Combining Gravity And Quantum Mechanics At Black Hole Horizons

Posted by in categories: cosmology, neuroscience, nuclear energy, particle physics, quantum physics, sustainability

Interesting…


To suggest that quantum mechanics and gravity are on the verge of being reconciled would be, to the physics world at least, as significant as the discover of splitting the atom. While splitting the atom might have led to the nuclear bomb, it also led to the technology of nuclear power, i.e. nuclear fission, which, if harnessed properly, creates a renewable and sustainable energy resource. The problem has always been that quantum mechanics — the rules that govern sub-atomic particles — and gravity, the rule that governs mass as we know it (the stuff we can touch and feel), do not agree with each other. The question has always been, what is it that “unifies” these two theories? Is quantum mechanics God playing dice, as Einstein suggested?

“God doesn’t play dice with the universe.”

Continue reading “Stephen Hawking’s Legacy Could Be ‘Holy Grail’ Of Physics: Combining Gravity And Quantum Mechanics At Black Hole Horizons” »

Nov 23, 2015

Particle Accelerators Could Soon Fit In A Shoebox

Posted by in categories: computing, particle physics

As the challenges of particle physics have become more and more complex, we’ve had to plan and build larger and larger machines to explore the tiny subatomic world. But now, an international group of physicists has developed a technology to miniaturize particle accelerators, which could revolutionize physics and the life sciences.

The team has received a $13.5 million (£9 million) grant to develop a prototype particle accelerator that will fit in a shoebox. The technology being developed is called “accelerator-on-a-chip”. Electrons are made to travel through a channel within a silica chip. Shining a laser onto the chip produces an electric field, and the field is modified by the ridges within the channel. This set-up dramatically accelerates the electrons moving through the channel.

The prototype is based on independent experiments from the SLAC National Accelerator Laboratory in California and Friedrich-Alexander University Erlangen-Nuremberg (FAU) in Germany. Both teams discovered that these chips are capable of accelerating electrons to relativistic speed no matter the speed at which the electron was travelling before entering the channel. Also, the technology is capable of producing a larger acceleration gradient than current labs, which could reduce the size of particle accelerators – 100 meters (330 feet) of accelerator-on-a-chip would produce an acceleration equivalent to the 3.2-kilometer (two miles) SLAC linear accelerator, which is the longest in the world.

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Nov 22, 2015

Scientists create single-molecule ‘nanosubmarines’ powered by light

Posted by in categories: entertainment, particle physics

In science-fiction movies like Fantastic Voyage and Innerspace, plucky individuals board microscopic submersibles and take a trip inside the human body… where predictably dramatic consequences ensue.

We’re not quite there yet, but it seems we’re getting close. Scientists in the US have developed nanosubmarines (aka. unimolecular submersible nanomachines) composed of a single molecule of just 244 atoms.

The nanosubs are powered by ultraviolet light, with the motor’s tail-like propeller – which operates more like a bacteria’s flagellum than a conventional motorised propeller – moving the nanomachines forward by 18 nanometres with each full revolution.

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Nov 21, 2015

Spooky Action Is Real: Bizarre Quantum Entanglement Confirmed in New Tests

Posted by in categories: particle physics, quantum physics

It just goes to show that one of the most potent weapons in science is the ability to keep an open, critical mind.


Two recent studies have confirmed that the “spooky action at a distance” that so upset Albert Einstein — the notion that two entangled particles separated by long distances can instantly affect each other — has been proven to work in a stunning array of different experimental setups.

One experiment closed two of the three loopholes in proofs of spooky action at a distance. Another found that quantum entanglement works over astonishingly large distances. And future tests are focused on making the final loophole as small as possible. [8 Ways You Can See Einstein’s Theory of Relativity in Real Life]

Continue reading “Spooky Action Is Real: Bizarre Quantum Entanglement Confirmed in New Tests” »

Nov 20, 2015

Quantum entanglement achieved at room temperature in semiconductor wafers

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

Entanglement is one of the strangest phenomena predicted by quantum mechanics, the theory that underlies most of modern physics. It says that two particles can be so inextricably connected that the state of one particle can instantly influence the state of the other, no matter how far apart they are.

Just one century ago, was at the center of intense theoretical debate, leaving scientists like Albert Einstein baffled. Today, however, entanglement is accepted as a fact of nature and is actively being explored as a resource for future technologies including quantum computers, quantum communication networks, and high-precision quantum sensors.

Entanglement is also one of nature’s most elusive phenomena. Producing entanglement between particles requires that they start out in a highly ordered state, which is disfavored by thermodynamics, the process that governs the interactions between heat and other forms of energy. This poses a particularly formidable challenge when trying to realize entanglement at the macroscopic scale, among huge numbers of particles.

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Nov 20, 2015

Moore Foundation Gives Stanford $13.5 Million To Build “Accelerator on a Chip”

Posted by in categories: biotech/medical, computing, electronics, mobile phones, particle physics, security

Today’s particle accelerators are massive machines, but physicists have been working on shrinking them down to tabletop scales for years. The Gordon and Betty Moore Foundation just awarded a $13.5 million grant to Stanford University to develop a working “accelerator on a chip” the size of a shoebox over the next five years.

The international collaboration will build on prior experiments by physicists at SLAC/Stanford and Germany’s Friedrich-Alexander University in Erlangen-Nuremberg. If successful, the prototype could usher in a new generation of compact particle accelerators that could fit on a laboratory bench, with potential applications in medical therapies, x-ray imaging, and even security scanner technologies.

The idea is to “do for particle accelerators what the microchip industry did for computers,” SLAC National Accelerator Laboratory physicist Joel England told Gizmodo. Computers used to fill entire rooms back when they relied on bulky vacuum tube technology. The invention of the transistor and subsequent development of the microchip made it possible to shrink computers down to laptop and cell phone scales. England envisions a day when we might be able to build a handheld particle accelerator, although “there’d be radiation issues, so you probably wouldn’t want to hold one in your hand.”

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Nov 20, 2015

Supercomputing the strange difference between matter and antimatter

Posted by in categories: particle physics, supercomputing

An international team of physicists including theorists from the U.S. Department of Energy’s (DOE) Brookhaven National Laboratory has published the first calculation of direct “CP” symmetry violation—how the behavior of subatomic particles (in this case, the decay of kaons) differs when matter is swapped out for antimatter. Should the prediction represented by this calculation not match experimental results, it would be conclusive evidence of new, unknown phenomena that lie outside of the Standard Model—physicists’ present understanding of the fundamental particles and the forces between them.

The current result—reported in the November 20 issue of Physical Review Letters —does not yet indicate such a difference between experiment and theory, but scientists expect the precision of the calculation to improve dramatically now that they’ve proven they can tackle the task. With increasing precision, such a difference—and new physics—might still emerge.

“This so called ‘direct’ symmetry violation is a tiny effect, showing up in just a few particle decays in a million,” said Brookhaven physicist Taku Izubuchi, a member of the team performing the calculation. Results from the first, less difficult part of this calculation were reported by the same group in 2012. However, it is only now, with completion of the second part of this calculation—which was hundreds of times more difficult than the first—that a comparison with the measured size of direct CP violation can be made. This final part of the calculation required more than 200 million core processing hours on supercomputers, “and would have required two thousand years using a laptop,” Izubuchi said.

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Nov 19, 2015

Dark matter might cause fundamental constants to change over time

Posted by in categories: cosmology, particle physics

(Phys.org)—The fundamental constants of nature—such as the speed of light, Planck’s constant, and Newton’s gravitational constant—are thought to be constant in time, as their name suggests. But scientists have questioned this assumption as far back as 1937, when Paul Dirac hypothesized that Newton’s gravitational constant might decrease over time.

Now in a new paper published in Physical Review Letters, Yevgeny V. Stadnik and Victor V. Flambaum at the University of New South Wales in Sydney, Australia, have theoretically shown that can cause the fundamental constants of nature to slowly evolve as well as oscillate due to oscillations in the dark matter field. This idea requires that the weakly interacting dark matter particles be able to interact a small amount with particles, which the scientists show is possible.

In their paper, the scientists considered a model in which dark matter is made of weakly interacting, low-mass particles. In the early Universe, according to the model, large numbers of such dark matter particles formed an oscillating field. Because these particles interact so weakly with standard model particles, they could have survived for billions of years and still exist today, forming what we know as dark matter.

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