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When physicists first thought up quantum computers in the 1980s, they sounded like a nice theoretical idea, but one probably destined to remain on paper. Then in 1995, 25 years ago this month, applied mathematician Peter Shor published a paper1 that changed that perception. Shor’s paper showed how quantum computers could overcome a crucial problem. The machines would process information as qubits — quantum versions of ordinary bits that can simultaneously be ‘0’ and ‘1’. But quantum states are notoriously vulnerable to noise, leading to loss of information. His error-correction technique — which detects errors caused by noise — showed...

SHANGHAI — More than a decade ago, Chinese physicist Pan Jian-Wei returned home from Europe to help oversee research into some of the most important technology of the 21st century. At a conference in Shanghai this summer, Pan and his team offered a rare peek at the work he described as a “revolution.” They spoke of the hacking-resistant communications networks they are building across China, the sensors they are designing to see through smog and around corners, and the prototype computers that may someday smash the computational power of any existing machine. All the gear is based on quantum technology...

The reality of quantum computing could be just three years away Quantum computing has moved out of the realm of theoretical physics and into the real world, but its potential and promise are still years away. Onstage at TechCrunch Disrupt SF, a powerhouse in the world of quantum research and a young upstart in the field presented visions for the future of the industry that illustrated both how far the industry has come and how far the technology has to go. For both Dario Gil, the chief operating officer of IBM Research and the company’s vice president of artificial intelligence...

Researchers have been able to confine light down to a space one atom, the smallest possible. This will pave the way to ultra-small optical switches, detectors and sensors. Light can function as an ultra-fast communication channel, for example between different sections of a computer chip, but it can also be used for ultra-sensitive sensors or on-chip nanoscale lasers. There is currently much research into how to further shrink devices that control and guide light. New techniques searching for ways to confine light into extremely tiny spaces, much smaller than current ones, have been on the rise. Researchers had previously found...

A company in California just proved that an exotic and potentially game-changing kind of computer can be used to perform a common form of machine learning. The feat raises hopes that quantum computers, which exploit the logic-defying principles of quantum physics to perform certain types of calculations at ridiculous speeds, could have a big impact on the hottest area of the tech industry: artificial intelligence. Researchers at Rigetti Computing, a company based in Berkeley, California, used one of its prototype quantum chips—a superconducting device housed within an elaborate super-chilled setup—to run what’s known as a clustering algorithm. Clustering is a...

IBM Q isn’t vaporware. It’s a project years-in-the-making that could help quantum computation reach its massive potential. The future of quantum computers may arrive sooner than you think. When news arrived of IBM’s move to offer the first commercially available universal quantum computer last week, it was characterized as a “handoff” from IBM Research to IBM Systems. According to the company’s CTO and vice president of quantum computing, technical strategy, and systems, Scott Crowder, that’s not entirely the case. “It’s not quite a ‘handoff,’ it’s really a partnership,” explained Crowder. “This is definitely a transition point from it being pure...

A seminal moment in the quantum technology field just happened: Google's team of scientists have simulated a hydrogen molecule from its quantum computers, a breakthrough that suggests it could “simulate even larger chemical systems,” writes one of Google Quantum’s engineers, Ryan Rabbush. The search engine’s achievement underscores the technology’s potential as Rabbush posits it can “revolutionize the design of solar cells, industrial catalysts, batteries, flexible electronics, medicines, materials and more.”

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).

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...

(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...

Google has announced it is developing next generation quantum computer chip as part of its plan to enable machines to think like humans. The internet company's Quantum Artificial Intelligence team, together with researcher John Martinis and his team at the University of California, will create the super-fast chip. They will work on a hardware initiative to design and build chips operating on sub-atomic levels, making them exponentially faster than processors in ordinary computers.

Science The Future May Be Getting Close to Reality in Vancouver, With D-Wave and General Fusion March 18, 2014, 2:11 PM PDT By Liz Gannes   Vancouver is a land of scenic harbors, tall mountains and startups trying to harness the limits of physics.In town for the TED conference, I had the occasion to visit two such companies yesterday: D-Wave and General Fusion. D-Wave, a quantum computing company, is all about the very cold and the rather tiny. It has built enormous refrigerators that each house a single chip, laced with “qubits” that can be in the superposition of...

A group of physicists at the University of Glasgow is claiming a first: taking photos of entangled photons. In this paper in Nature (hooray for free access!), they explain that their 201 x 201 pixel images captured around 2,500 different entangled quantum states. The entangled photons were imaged using different lens configurations to capture correlations of position and momentum – the characteristics (to shorthand Heisenberg’s uncertainty principle) that mutually preclude excessive knowledge about a given quantum system. From the 100,000 images taken by their setup (pictured*), the scientists say they were able to observe 2,500 states which they described as...

A controllable transistor engineered from a single phosphorus atom. The atom, shown here in the center of an image from a computer model, sits in a channel in a silicon crystal. The atomic-sized transistor and wires might allow researchers to control gated qubits of information in future quantum computers. (Credit: Purdue University)The smallest transistor ever built has been created using a single phosphorous atom by an international team of researchers at the University of New South Wales, Purdue University and the University of Melbourne.The latest Intel chip, the “Sandy Bridge,” uses a manufacturing process to place 2.3 billion transistors 32...

Last Friday, I realized the sort of place I work in: an academic Computer Science institute that bears more than a passing resemblence to the ficticious TV town of 'Eureka'. We don't have flying cars, or intelligent, rebellious, precocious attack bots, but we do have some cool stuff. Take the 128-QuBit Quantum Computer housed the ground floor of parking lot where a sandwich shop used to be, for example. This is the next generation of computers, using the superposition effects of quantum mechanics to process vastly many more states than our current 'classical' computers can accomplish. This is the sort...

Quantum physicists at the Massachusetts Institute of Technology believe it is possible to create a time machine which could affect the past without creating a "grandfather paradox".Scientists have for some years been able to 'teleport' quantum states from one place to another. Now Seth Lloyd and his MIT team say that, using the same principles and a further strange quantum effect known as 'postselection', it should be possible to do the same backwards in time. Lloyd told the Technology Review: "It is possible for particles (and, in principle, people) to tunnel from the future to the past."

Projects at the University of California at Santa Barbara will focus on developing new quantum measurement techniques to manipulate and read out single electron spins in diamond. The projects will also focus on the on-chip integration of single electron spins with photonics, for communication . Additionally, the project aims to build a world-class research facility for the creation of synthetic crystal diamond and diamond heterostructure materials and devices. Diamonds fabricated by the team will complement many ongoing research initiatives on campus and around the world, including programs working towards solid-state lighting, nanoelectronics, and atomic-level storage.

Scientists in Japan have made a key step toward the development of a quantum computer -- a still largely hypothetical device that would be dramatically more powerful than today's supercomputers -- according to Japanese electronics giant NEC Corp. In what they claimed was a world first, researchers at NEC and the state-funded Institute of Physical and Chemical Research successfully demonstrated a circuit that can control the state of a pair of elemental particles and how strongly they interact with one another. Being able to control these particles -- called "qubits" -- in this fashion may help scientists to build a...

Twenty years before most scientists expected it, a commercial company has announceda quantum computer that promises to massively speed up searches and optimisation calculations. D-Wave of British Columbia has promised to demonstrate a quantum computer next Tuesday, that can carry out 64,000 calculations simultaneously (in parallel "universes"), thanks to a new technique which rethinks the already-uncanny world of quantum computing. But the academic world is taking a wait-and-see approach. D-Wave is the world's only "commercial" quantum computing company, backed by more than $20 million of venture capital (there are more commercial ventures in the related field of quantum cryptography). Its...