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Schrödinger's cat now has a second box to play in, thanks to an international team of physicists that has created a two-mode "Schrödinger's cat state" for the first time. The experiment brings together two purely quantum properties, in that the "cat" (i.e. the photons) is simultaneously "alive and dead" (in a superposition of states) while also in two locations at once (the two boxes are entangled with one another).

An experiment claims to have invalidated a decades-old criticism against pilot-wave theory, an alternative formulation of quantum mechanics that avoids the most baffling features of the subatomic universe. Of the many counterintuitive features of quantum mechanics, perhaps the most challenging to our notions of common sense is that particles do not have locations until they are observed. This is exactly what the standard view of quantum mechanics, often called the Copenhagen interpretation, asks us to believe. Instead of the clear-cut positions and movements of Newtonian physics, we have a cloud of probabilities described by a mathematical structure known as a...

With its ideas of particles zipping in and out of existence, quantum mechanics is probably the kookiest-sounding theory in science. And our understanding of it is little helped by the mysterious "probability fields" most physicists say dictate the zipping. But a more intuitive picture may lie beneath. As new research demonstrates, beneath the shroud of probability, particles can in fact be viewed as behaving like billiard balls rolling along a table - although in surreal fashion. The result helps resurrect an 80-year-old picture of quantum mechanics, and provides one of the most stirring demonstrations yet of an effect Einstein called...

In a breakthrough in quantum physics, scientists were able to create the phenomenon of quantum entanglement macroscopically using large magnets at room temperature. ... scientists working at the University of Chicago and the Argonne National Laboratory revealed that they were able to create quantum entanglement at a macroscopic level at room temperature on a semiconductor chip, using atomic nuclei and the application of relatively small magnetic fields. Their breakthrough, which is published in Science Advances, is not only significant in what they accomplished but also how they accomplished it. In quantum physics, the creation of entanglement in particles larger and...

It might seem like more of a magic trick than real science, but physicists have successfully made a 'cloud' of atoms exist in two separate places at the same time. The laws of standard physics dictate an object can't be in two places at once, but the researchers have exploited a quirk of tiny particles that exist in the quantum world, and applied this to atoms. Their breakthrough raises the prospect of being able to send not just information but perhaps even 'recreate' physical objects over large distances in a form of teleportation.

The Universe we know and love — with Einstein’s General Relativity as our theory of gravity and quantum field theories of the other three forces — has a problem that we don’t often talk about: it’s incomplete, and we know it. Einstein’s theory on its own is just fine, describing how matter-and-energy relate to the curvature of space-and-time. Quantum field theories on their own are fine as well, describing how particles interact and experience forces. Normally, the quantum field theory calculations are done in flat space, where spacetime isn’t curved. We can do them in the curved space described by...

This week, Google announced a breakthrough that could prove its quantum computer is actually using quantum mechanics. When researchers gave the D-Wave 2X a carefully crafted test problem, the 1,000-qubit computer solved it 100,000,000 times faster than a classical computer could. Quite a few tech giants and government organizations are investing in quantum computing. And many of them, including Google, NASA, and Lockheed Martin, are working with the commercial quantum computers built by D-Wave. The idea is that these devices can harness the counterintuitive effects of quantum mechanics to solve problems faster than conventional computers, which could potentially improve artificial...

The actual problem that computer scientists threw at the D-Wave Two is pretty esoteric. To oversimplify it, they asked the machine to pick the optimum choice out of a large jumble of information with nearly 1,000 variables. Such optimization problems, which involve weighing multiple choices against each other, should be far, far easier for quantum computers to crunch. That's because the basis of quantum computation, the qubit, uses the odd physics of quantum mechanic to hold information as a zero, one, or a superposition of both. Again, to over-simplify things, this allows quantum computers to consider a vast number of...

Two years ago Google and NASA bought a D-Wave 2X quantum computing system and the Chocolate Factory has now pronounced itself very pleased with the results. "We found that for problem instances involving nearly 1000 binary variables, quantum annealing significantly outperforms its classical counterpart, simulated annealing. It is more than 108 times faster than simulated annealing running on a single core," Hartmut Neven, Google's director of engineering reported on Tuesday. Now comparing almost any operation against a single core is a bit of a fudge, but the results show that Google and NASA certainly feel D-Wave's take on quantum computing...

Researchers have written quantum code on a silicon chip for the first time And so it begins... FIONA MACDONALD 17 NOV 2015           For the first time, Australian engineers have demonstrated that they can write and manipulate the quantum version of computer code on a silicon microchip. This was done by entangling two quantum bits with the highest accuracy ever recorded, and it means that we can now start to program for the super-powerful quantum computers of the future.Engineers code regular computers using traditional bits, which can be in one of two states: 1 or 0. Together, two bits...

The significant advance, by a team at the University of New South Wales (UNSW) in Sydney appears today in the international journal Nature. "What we have is a game changer," said team leader Andrew Dzurak, Scientia Professor and Director of the Australian National Fabrication Facility at UNSW. "We've demonstrated a two-qubit logic gate - the central building block of a quantum computer - and, significantly, done it in silicon. Because we use essentially the same device technology as existing computer chips, we believe it will be much easier to manufacture a full-scale processor chip than for any of the leading...

Above: IBM's carbon nanotubes have tiny circuits that are fractions of a meter apart.Image Credit: IBM Carbon nanotubes are the leading candidate to replace silicon in semiconductor chips after the decades-long run of silicon electronics runs out. And IBM is hoping to usher along that transition with a new breakthrough being announced today.In the October 2 issue of the journal Science, IBM researchers say they have overcome one of the most daunting challenges around carbon nanotube transistors, which are the building blocks of electronic circuits with dimensions that are measured in billionths of a meter. Carbon nanotubes may be...

IBM boffins have been given a tidy $3bn cash pile to solve a problem that lurks not too far in our future. That problem is the imminent breakdown in conventional chip operation and chip materials as we shrink transistor gates from today's 14nm process size to 10nm and 7nm. At around 7nm, which most industry observers expect we will hit in the early 2020s, things start to get really unpleasant. More and more jostling electrons jump in and out of gates against processor designers' wishes, leading to a frustrating problem known as gate current leakage. ... These investment areas include:...

Schrödinger’s bacterium: physicists plan to put a microbe in two places at the same time Okay, this is WAY above my pay grade, but I’ve been sent articles on this by several authors, including an explanation at the Guardian. It’s a description by two theoretical physicists of an experiment that uses quantum superposition to put a bacterium in two places at the same time. They plan to collaborate with experimentalists to actually carry it out. Here’s what the Guardian says about it: The researchers plan to build on the work of others at the University of Colorado who showed in 2013 that a tiny, vibrating...

(Phys.org)—Due to quantum effects, it's possible to build a quantum computer that computes without running—or as the scientists explain, "the result of a computation may be learned without actually running the computer." So far, however, the efficiency of this process, which is called counterfactual computation (CFC), has had an upper limit of 50%, limiting its practical applications. Now in a new paper, scientists have experimentally demonstrated a slightly different version called a "generalized CFC" that has an efficiency of 85% with the potential to reach 100%. This improvement opens the doors to realizing a much greater variety of applications, such...

Typically when referring to electrical current, an image of electrons moving through a metallic wire is conjured. Using the spin Seebeck effect (SSE), it is possible to create a current of pure spin (a quantum property of electrons related to its magnetic moment) in magnetic insulators. However, this work demonstrates that the SSE is not limited to magnetic insulators but also occurs in a class of materials known as paramagnets. Since magnetic moments within paramagnets do not interact with each other like in conventional ferromagnets, and thus do not hold their magnetization when an external magnetic field is removed, this...

An exotic particle made up of five quarks has been discovered a decade after experiments seemed to rule out its existence. The short-lived ‘pentaquark’ was spotted by researchers analysing data on the decay of unstable particles in the LHCb experiment at the Large Hadron Collider (LHC) at CERN, Europe’s particle-physics laboratory near Geneva. The finding, says LHCb spokesperson Guy Wilkinson, opens a new era in physicists’ understanding of the strong nuclear force that holds atomic nuclei together. “The pentaquark is not just any new particle — it represents a way to aggregate quarks, namely the fundamental constituents of ordinary protons...

Einstein's theory of time and space will celebrate its 100th anniversary this year. Even today it captures the imagination of scientists. In an international collaboration, researchers from the universities of Vienna, Harvard and Queensland have now discovered that this world-famous theory can explain yet another puzzling phenomenon: the transition from quantum behavior to our classical, everyday world. Their results are published in the journal Nature Physics. In 1915 Albert Einstein formulated the theory of general relativity which fundamentally changed our understanding of gravity. He explained gravity as the manifestation of the curvature of space and time. Einstein's theory predicts that...

The bizarre nature of reality as laid out by quantum theory has survived another test, with scientists performing a famous experiment and proving that reality does not exist until it is measured. Physicists at The Australian National University (ANU) have conducted John Wheeler's delayed-choice thought experiment, which involves a moving object that is given the choice to act like a particle or a wave. Wheeler's experiment then asks - at which point does the object decide? Common sense says the object is either wave-like or particle-like, independent of how we measure it. But quantum physics predicts that whether you observe...

Owen Maroney worries that physicists have spent the better part of a century engaging in fraud. Ever since they invented quantum theory in the early 1900s, explains Maroney, who is himself a physicist at the University of Oxford, UK, they have been talking about how strange it is — how it allows particles and atoms to move in many directions at once, for example, or to spin clockwise and anticlockwise simultaneously. But talk is not proof, says Maroney. “If we tell the public that quantum theory is weird, we better go out and test that's actually true,” he says. “Otherwise...