Archive for the ‘quantum physics’ category: Page 584
Feb 1, 2019
Scientists ‘hijack’ open-access quantum computer to tease out quantum secrets
Posted by Genevieve Klien in categories: computing, particle physics, quantum physics
The rules of quantum mechanics describe how atoms and molecules act very differently from the world around us. Scientists have made progress toward teasing out these rules—essential for finding ways to make new molecules and better technology—but some are so complex that they evade experimental verification.
With the advent of open-access quantum computers, scientists at the University of Chicago saw an opportunity to do a very unusual experiment to test some of these quantum principles. Their study, which appeared Jan. 31 in Nature Communications Physics, essentially hijacks a quantum computer to discover fundamental truths about the quantum behavior of electrons in molecules.
“Quantum computing is a really exciting realm to explore fundamental questions. It allows us to observe aspects of quantum theory that are absolutely untouchable with classical computers,” said Prof. David Mazziotti, professor of chemistry and author on the paper.
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Jan 31, 2019
Dark Energy Gets Weirder: Mysterious Force May Vary Over Time
Posted by Quinn Sena in categories: cosmology, quantum physics
Dark energy is apparently even more mysterious than astronomers had thought.
Scientists first proposed the existence of this invisible force two decades ago, to explain the surprising discovery that the universe’s expansion is accelerating. (Surprising and incredibly important; the find netted three researchers the Nobel Prize in physics in 2011.)
The most-used astrophysical model of the universe’s structure and evolution regards dark energy as a constant. Indeed, many astronomers believe it to be the cosmological constant, which Einstein posited in 1917 as part of his theory of general relativity. [The History & Structure of the Universe in Pictures].
Jan 30, 2019
Is empirical testing of string theory possible?
Posted by Paul Battista in category: quantum physics
Jan 30, 2019
New quantum structures in super-chilled helium may mirror early days of universe
Posted by Paul Battista in categories: cosmology, quantum physics
For the first time, researchers have documented the long-predicted occurrence of ‘walls bound by strings’ in superfluid helium-3. The existence of such an object, originally foreseen by cosmology theorists, may help explaining how the universe cooled down after the Big Bang. With the newfound ability to recreate these structures in the lab, earth-based scientists finally have a way to study some of the possible scenarios that might have taken place in the early universe more closely.
Jan 30, 2019
How does a quantum particle see the world?
Posted by Xavier Rosseel in categories: particle physics, quantum physics, transportation
Researchers at the University of Vienna study the relevance of quantum reference frames for the symmetries of the world.
According to one of the most fundamental principles in physics, an observer on a moving train uses the same laws to describe a ball on the platform as an observer standing on the platform – physical laws are independent on the choice of a reference frame. Reference frames such as the train and the platform are physical systems and ultimately follow quantum-mechanical rules. They can be, for example, in a quantum state of superposition of different positions at once. So, what would the description of the ball look like for an observer on such a “quantum platform”? Researchers at the University of Vienna and the Austrian Academy of Sciences proved that whether an object (in our example, the ball) shows quantum features depends on the reference frame. The physical laws, however, are still independent of it. The results are published in Nature Communications.
Physical systems are always described relative to a reference frame. For example, a ball bouncing on a railway platform can be observed either from the platform itself or from a passing train. A fundamental principle of physics, the principle of General Covariance, states that the laws of physics which describe the motion of the ball do not depend on the reference frame of the observer. This principle has been crucial in the description of motion since Galileo and central to the development of Einstein’s theory of relativity. It entails information about symmetries of the laws of physics as seen from different reference frames.
Jan 29, 2019
New quantum system could help design better spintronics
Posted by Genevieve Klien in categories: computing, particle physics, quantum physics
Researchers have created a new testing ground for quantum systems in which they can literally turn certain particle interactions on and off, potentially paving the way for advances in spintronics.
Spin transport electronics have the potential to revolutionize electronic devices as we know them, especially when it comes to computing. While standard electronics use an electron’s charge to encode information, spintronic devices rely on another intrinsic property of the electron: its spin.
Spintronics could be faster and more reliable than conventional electronics, as spin can be changed quickly and these devices use less power. However, the field is young and there are many questions researchers need to solve to improve their control of spin information. One of the most complex questions plaguing the field is how the signal carried by particles with spin, known as spin current, decays over time.
Jan 29, 2019
Scientists Generate Quantum Entanglement in Space For the First Time
Posted by Paul Battista in categories: quantum physics, space
The entangled photons were beamed to three ground stations across China, each separated by more than 700 miles—a new record.
Jan 29, 2019
Quantum Computing Research at NASA
Posted by Genevieve Klien in categories: quantum physics, supercomputing
A participation in the annual Supercomputing conference taking place in Salt Lake City, UT, USA from November 14–17, 2016.
Jan 29, 2019
Quantum structure of buckyballs
Posted by Caycee Dee Neely in categories: computing, particle physics, quantum physics
Buckyballs! We love them.
JILA researchers have measured hundreds of individual quantum energy levels in the buckyball, a spherical cage of 60 carbon atoms. It’s the largest molecule that has ever been analyzed at this level of experimental detail in the history of quantum mechanics. Fully understanding and controlling this molecule’s quantum details could lead to new scientific fields and applications, such as an entire quantum computer contained in a single buckyball.