Archive for the ‘quantum physics’ category: Page 577
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.
Jan 28, 2019
All-photonic quantum repeaters could lead to a faster, more secure global quantum internet
Posted by James Christian Smith in categories: engineering, internet, quantum physics
Engineering researchers have demonstrated proof-of-principle for a device that could serve as the backbone of a future quantum Internet. University of Toronto Engineering professor Hoi-Kwong Lo and his collaborators have developed a prototype for a key element for all-photonic quantum repeaters, a critical step in long-distance quantum communication.
Jan 26, 2019
Battling AI algorithm tested on a quantum computer for first time
Posted by Genevieve Klien in categories: information science, quantum physics, robotics/AI
One of the most powerful techniques in machine learning, generative adversarial networks, has been tested on a quantum computer for the first time.
Jan 26, 2019
Quantum Theory Bends The Limits of Physics, Showing Two-Way Signaling May Be Possible
Posted by Paul Battista in categories: particle physics, quantum physics
Quantum physics just beat classical physics again.
A single quantum particle can send a two-way signal, scientists have discovered — something that’s impossible in classical physics. That means a particle can essentially send messages to itself thanks to the whacky state of uncertainty known as superposition.
Superposition states that one particle can occupy two positions at once, and that’s how the two-way communication happens.