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Apr 3, 2016

New quantum distillation method allows measuring coherence of quantum states

Posted by in categories: particle physics, quantum physics

One of the main principles of quantum physics is the superposition of states. Systems are simultaneously in different states, i.e. “alive and dead” at the same time such as Schrödinger’s cat, until someone measures them and the system opts for one of the possibilities. As long as the superposition lasts the system is said to be in a coherent state. In real systems, sets of diverse elemental particles or atoms existing in a state of superposition, for example, in different positions simultaneously, with different levels of energy, or with two opposite spin orientations, have weak coherence: the superposition is broken easily by the vibrations associated with temperature and the interactions with the environment.

In the scientific article, researchers from the Universitat Autònoma de Barcelona Department of Physics Andreas Winter and Dong Yang propose a groundbreaking method with which to measure the degree of coherence in any given quantum state. The researchers created simple formulas to calculate how much “pure coherence” is contained in a given quantum state, by answering two fundamental questions: How efficiently can one transform the state into “pure coherence”? And how efficient is the reverse process?

“At first the quantum state must be distilled. We must see how much coherence can be extracted from it,” explains Andreas Winter, to later “once again form a noisy state in which the coherence is diluted.” The distillation and dilution process allows measuring the strength of coherence of the initial state of superposition with experiments which can be tailored to each particular case. This is an outstanding contribution to the study of quantum physics given that “traditionally, to measure the degree of coherence of a superposition it was necessary to be able to measure the visibility of interference fringes, linked to standardised experiments,” Winter highlights. “With our approach, in contrast, the experiment can be adapted to every state in order to make the quantum coherence manifest itself better.”

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Apr 3, 2016

Interesting Futurism Animation 27

Posted by in category: futurism

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Apr 3, 2016

IBM’s resistive computing could massively accelerate AI — and get us closer to Asimov’s Positronic Brain

Posted by in categories: computing, robotics/AI

Neural networks have enabled a revolution in machine learning. IBM researchers show how resistive computing can be used to make them massively more powerful.

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Apr 3, 2016

Will Humans Ever Build Starships?

Posted by in category: space travel

The technology to make starships work is still way off — but that isn’t stopping us from thinking about how it might work.

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Apr 3, 2016

Tesla Unveils Model 3 | Tesla Motors

Posted by in categories: automation, business, Elon Musk, energy, innovation, robotics/AI, science, sustainability, transportation

Apr 3, 2016

New link between quantum computing and black hole may solve information loss problem

Posted by in categories: computing, cosmology, quantum physics

Some more words on this idea that black holes are quantum computers.

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Apr 2, 2016

Device turns your phone into 3D printer

Posted by in categories: 3D printing, mobile phones

This $99 device turns your phone into a 3D printer.

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Apr 2, 2016

Watch a Tesla drive itself through I-65 rush hour traffic

Posted by in category: transportation

Auto-piloting Tesla: awesome or terrifying?

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Apr 2, 2016

There Are Some Super Shady Things in Oculus Rift’s Terms of Service

Posted by in categories: ethics, virtual reality

This is NOT the way to encourage people to use this device, nor develop anything for it at all. Shame on them!

“By submitting User Content through the Services, you grant Oculus a worldwide, irrevocable, perpetual (i.e. lasting forever), non-exclusive, transferable, royalty-free and fully sublicensable (i.e. we can grant this right to others) right to use, copy, display, store, adapt, publicly perform and distribute such User Content in connection with the Services. You irrevocably consent to any and all acts or omissions by us or persons authorized by us that may infringe any moral right (or analogous right) in your User Content.”

The Oculus Rift is starting to ship, and we’re pretty happy with it. While it’s cool, like any interesting gadget, it’s worth looking through the Terms of Service, because there are some worrisome things included.

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Apr 2, 2016

All quantum communication involves nonlocality

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

Researchers of CWI, University of Gdansk, Gdansk University of Technology, Adam Mickiewicz University and the University of Cambridge have proven that quantum communication is based on nonlocality. They show that whenever quantum communication is more efficient than classical communication, it must be possible find a nonlocal correlation somewhere. Their paper ‘Quantum communication complexity advantage implies violation of a Bell inequality’, appeared in this month’s issue of the influential journal PNAS.

It has long been known that predicts counterintuitive effects such as instantaneous interaction at a distance between entangled particles. This teleportation effect, which Albert Einstein famously called ‘spooky action at a distance,’ was long thought to show that the theory of quantum mechanics was incomplete. However, in 1964, physicist J.S. Bell proved that no theory involving the principle of locality can ever reproduce all predictions of quantum mechanics. In other words, it is impossible to find classical explanations for quantum correlations. This evidence for the existence of nonlocality became known as Bell’s inequality.

For a long time, the existence of was merely of interest to philosophically minded physicists, and was considered an exotic peculiarity rather than a useful resource for practical problems in physics or computer science. This has changed dramatically in recent years. Quantum correlation proved to be very useful in information processing. In several communication tasks, using quantum effects substantially reduced the communication complexity: the minimum number of steps necessary to complete a certain task between two parties. In such cases, there is a so-called quantum advantage in communication complexity.

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