Quantum computers could revolutionize the way we tackle problems that stump even the best classical computers.
Single atom transistor recently introduced has been seen as a tool that could lead the way to building a quantum computer. For general introduction how quantum computer work, read A tale of two qubits: how quantum computers work article.
D-Wave Announces Commercially Available Quantum Computer article tells that computing company D-Wave has announced that they’re selling a quantum computing system commercially, which they’re calling the D-Wave One. D-Wave system comes equipped with a 128-qubit processor that’s designed to perform discrete optimization operations. The processor uses quantum annealing to perform these operations.
D-Wave is advertisting a number of different applications for its quantum computing system, primarily in the field of artificial intelligence. According to the company, its system can handle virtually any AI application that can be translated to a Markov random field.
Learning to program the D-Wave One blog article tells that the processor in the D-Wave One – codenamed Rainier – is designed to perform a single mathematical operation called discrete optimization. It is a special purpose processor. When writing applications the D-Wave One is used only for the steps in your task that involve solving optimization problems. All the other parts of your code still run on your conventional systems of choice. Rainier solves optimization problems using quantum annealing (QA), which is a class of problem solving approaches that use quantum effects to help get better solutions, faster. Learning to program the D-Wave One is the first in a series of blog posts describing the algorithms we have run on D-Wave quantum computers, and how to use these to build interesting applications.
But is this the start of the quantum computers era? Maybe not. D-Wave Announces Commercially Available Quantum Computer article comments tell a story that this computer might not be the quantum computer you might be waiting for. It seem that the name “quantum computer” is a bit misleading for this product. There are serious controversies around the working and “quantumness” of the machine. D-Wave has been heavily criticized by some scientists in the quantum computing field. First sale for quantum computing article tells that uncertainty persists around how the impressive black monolith known as D-Wave One actually works. Computer scientists have long questioned whether D-Wave’s systems truly exploit quantum physics on their products.
Slashdot article D-Wave Announces Commercially Available Quantum Computer comments tell that this has the same central problem as before. D-Wave’s computers haven’t demonstrated that their commercial bits are entangled. There’s no way to really distinguish what they are doing from essentially classical simulated annealing. Recommended reading that is skeptical of D-Wave’s claims is much of what Scott Aaronson has wrote about them. See for example http://www.scottaaronson.com/blog/?p=639, http://www.scottaaronson.com/blog/?p=198 although interestingly after he visited D-Wave’s labs in person his views changed slightly and became slightly more sympathetic to them http://www.scottaaronson.com/blog/?p=954.
So it is hard to say if the “128 qubits” part is snake oil or for real. If the 128 “qubits” aren’t entangled at all, which means it is useless for any of the quantum algorithms that one generally thinks of. It seem that this device simply has 128 separate “qubits” that are queried individually, and is, essentially an augmented classical computer that gains a few minor advantages in some very specific algorithms (i.e. the quantum annealing algorithm) due to this qubit querying, but is otherwise indistinguishable from a really expensive classical computer for any other purpose. This has the same central problem as before: D-Wave’s computers haven’t demonstrated that their commercial bits are entangled.
Rather than constantly adding more qubits and issuing more hard-to-evaluate announcements, while leaving the scientific characterization of its devices in a state of limbo, why doesn’t D-Wave just focus all its efforts on demonstrating entanglement, or otherwise getting stronger evidence for a quantum role in the apparent speedup? There’s a reason why academic quantum computing groups focus on pushing down decoherence and demonstrating entanglement in 2, 3, or 4 qubits: because that way, at least you know that the qubits are qubits! Suppose D-Wave were marketing a classical, special-purpose, $10-million computer designed to perform simulated annealing, for 90-bit Ising spin glass problems with a certain fixed topology, somewhat better than an off-the-shelf computing cluster. Would there be even 5% of the public interest that there is now?
Scientists Build First Working Quantum Network
http://www.pcmag.com/article2/0,2817,2402931,00.asp
Scientists at the Quantum Dynamics division of the Max Planck Institute of Quantum Optics (MPQ) in Garching, Germany announced Wednesday that they have built the very first, elementary quantum network comprised of a pair of entangled atoms that transmit information to each other via single photons.
That and a couple of bucks will get you a cup of coffee, plus anything from a perfectly secure data exchange system to the massive scaling via distributed processing of the already mind-bogglingly powerful, if theoretical, potential of a standalone quantum computer.
These are indeed heady days for the pioneers of quantum computing, with each news cycle seemingly bringing forth a major breakthrough in a subatomic frontier that appears poised to revolutionize how our calculating machines deliver us everything from satellite mapping to LOLcats.
“This approach to quantum networking is particularly promising because it provides a clear perspective for scalability,” Rempe told the journal. His colleague and leader of the experiment, Dr. Stephan Ritter, added, “We were able to prove that the quantum states can be transferred much better than possible with any classical network.”
The team was able to fix their atoms in optical cavities, basically a couple of highly reflective mirrors a short distance from each other, by means of fine-tuned laser beams.
Photons entering the cavity bounce around the mirrors “several thousand times,” which actually enhances the atom-photon interaction and enables the network node atoms to absorb the photon-based data packets “coherently and with high efficiency,” according to the scientists.
Quantum networking is the practical application of experimental quantum cryptography, like the “blind quantum computing” demonstration by another team of researchers at the University of Vienna’s Center for Quantum Science and Technology earlier this year, which involved transmitting an algorithm to acomputer, running it, and receiving it back without the computer’s operator being able to snoop on those operations.
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Weird! Quantum Entanglement Can Reach into the Past
https://developers.google.com/speed/articles/spdy-for-mobile
Spooky quantum entanglement just got spookier.
Entanglement is a weird statewhere two particles remain intimately connected, even when separated over vast distances, like two die that must always show the same numbers when rolled.
For the first time, scientists have entangled particles after they’ve been measured and may no longer even exist.
“Whether these two particles are entangled or separable has been decided after they have been measured,”
Essentially, the scientists showed that future actions may influence past events, at least when it comes to the messy, mind-bending world of quantum physics.
In the quantum world, things behave differently than they do in the real, macroscopic world we can see and touch around us.
Is the Age of Silicon Computing Coming to an End? Physicist Michio Kaku Says “Yes”
http://www.dailygalaxy.com/my_weblog/2012/05/is-the-age-of-silicon-coming-to-an-end-physicist-michio-kaku-says-yes.html
Traditional computing, with its ever more microscopic circuitry etched in silicon, will soon reach a final barrier: Moore’s law, which dictates that the amount of computing power you can squeeze into the same space will double every 18 months, is on course to run smack into a silicon wall due to overheating, caused by electrical charges running through ever more tightly packed circuits.
“In about ten years or so, we will see the collapse of Moore’s Law. In fact, already, already we see a slowing down of Moore’s Law,” says world-renowned physicist, Michio Kaku. “Computer power simply cannot maintain its rapid exponential rise using standard silicon technology.”
Despite Intel’s recent advances with tri-gate processors, Kaku argues in a video interview with Big Think, that the company has merely delayed the inevitable: the law’s collapse due to heat and leakage issues.
“So there is an ultimate limit set by the laws of thermal dynamics and set by the laws of quantum mechanics as to how much computing power you can do with silicon,” says Kaku, noting “That’s the reason why the age of silicon will eventually come to a close,” and arguing that Moore’s Law could “flatten out completely” by 2022.”
Kaku see several alternatives to the demise of Moores Law: protein computers, DNA computers, optical computers, quantum computers and molecular computers.
“If I were to put money on the table I would say that in the next ten years as Moore’s Law slows down, we will tweak it. We will tweak it with three-dimensional chips, maybe optical chips, tweak it with known technology pushing the limits, squeezing what we can. Sooner or later even three-dimensional chips, even parallel processing, will be exhausted and we’ll have to go to the post-silicon era,” says Kaku.
Kaku concludes that when Moore’s Law finally collapses by the end of the next decade, we’ll “simply tweak it a bit with chip-like computers in three dimensions. We may have to go to molecular computers and perhaps late in the 21st century quantum computers.”
We’ll place our bets on quantum computing.
To leapfrog the silicon wall, we have to figure out how to manipulate the brain-bending rules of the quantum realm – an Alice in Wonderland world of subatomic particles that can be in two places at once. Where a classical computer obeys the well understood laws of classical physics, a quantum computer is a device that harnesses physical phenomenon unique to quantum mechanics (especially quantum interference) to realize a fundamentally new mode of information processing.
The fundamental unit of information in quantum computing (called a quantum bit or qubit), is not binary but rather more quaternary in nature, which differs radically from the laws of classical physics.A qubit can exist not only in a state corresponding to the logical state 0 or 1 as in a classical bit, but also in states corresponding to a blend or superposition of these classical states.
In other words, a qubit can exist as a zero, a one, or simultaneously as both 0 and 1, with a numerical coefficient representing the probability for each state.
Franken-Physics: Atoms Split in Two & Put Back Together
http://www.livescience.com/20926-quantum-physics-atoms-split.html
Physicists have just upped their ante: Not only have they split atoms but, even trickier, they’ve put them back together.
Their secret? Quantum physics.
A team of scientists was able to “split” an atom into its two possible spin states, up and down, and measure the difference between them even after the atom resumed the properties of a single state.
The research wasn’t just playtime for quantum physicists: It could be a steppingstone toward the development of a quantum computer
In the classic double-slit experiment, atoms are fired at a wall with two breaks in it, and they pass through to the other side, where they hit a detector, creating the kind of interference pattern expected from a wave. If atoms behaved the way we intuitively expect particles to behave, they should emerge out of one slit or the other, with no interference pattern. As more and more atoms passed through the slits, there should be a cluster of them around the two points behind the slits.
Since this is quantum mechanics, that’s not what happens.
Instead, there’s an interference pattern that shows peaks and valleys. The atoms behave like light waves. The atom is in two places at once.
But if you try to see the atom in one or both places, it “collapses” into one, as the act of observing it determines its fate; hence, the interference pattern disappears.
In the experiment at Bonn, the researchers fired two lasers in sequence at a single atom of cesium, moving it to the left or right. The lasers allowed the researchers to control the movement of the atom precisely
Each atom has a spin state, which is either up or down. By moving the atom in two directions at once (using both lasers), the scientists were able to make it “split.”
It was in two states at once — up and down.
It’s not possible to see both states at once. If one were to try to measure the state of the atom, it would “collapse” into a single state.
Since atoms — and other quantum particles — behave like waves, they have phases, just as waves do.
n addition to measuring that phase difference, the researchers also saw “delocalization” — the double path through space the atom takes — at a greater distance than ever before, on the scale of micrometers as opposed to nanometers.
It’s this dual nature, called a superposed state, of atoms that would make quantum computers so powerful. The bits (known as “qubits”) could be in more than one state at once, allowing for calculations that would take ordinary computers an extremely long time. It also means that quantum computers could be useful for simulating other quantum systems.
Quantum Microphone
http://www.edn.com/electronics-blogs/anablog/4375473/Quantum-Microphone
Physicists from Chalmers University of Technology in Sweden, led by Per Delsing, have demonstrated a new kind of detector for sound at the level of quietness of quantum mechanics.
This ushers in a new class of quantum hybrid circuits that mix acoustic elements with electrical ones
The “quantum microphone” is based on a single electron transistor, that is, a transistor where the current passes one electron at a time. The acoustic waves studied by the research team propagate over the surface of a crystalline microchip, and resemble the ripples formed on a pond when a pebble is thrown into it.
The wavelength of the sound is a mere 3 micrometers, but the detector is even smaller, and capable of rapidly sensing the acoustic waves as they pass by
The detector is sensitive to waves with peak heights of a few percent of a proton diameter, levels so quiet that sound can be governed by quantum law rather than classical mechanics, much in the same way as light.
“The experiment is done on classical acoustic waves, but it shows that we have everything in place to begin studies of proper quantum-acoustics, and nobody has attempted that before”, says Martin Gustafsson, PhD student and first author of the article.
IBM Scientists “Waltz” Closer to Using Spintronics in Computing
http://www-03.ibm.com/press/us/en/pressrelease/38566.wss
- IBM Research is the first to synchronize electron spins and image the formation of a persistent spin helix.
- Spintronics could enable a new class of magnetic-based semiconductor transistors resulting in more energy efficient electronic devices.
The Spintronics Waltz
A previously unknown aspect of physics, the scientists observed how electron spins move tens of micrometers in a semiconductor with their orientations synchronously rotating along the path similar to a couple dancing the waltz, the famous Viennese ballroom dance where couples rotate.
IBM scientists imaged the synchronous ‘waltz’ of the electron spins by using a time-resolved scanning microscope technique. The synchronization of the electron spin rotation made it possible to observe the spins travel for more than 10 micrometers or one-hundredth of a millimeter, increasing the possibility to use the spin for processing logical operations, both fast and energy-efficiently.
D-Wave goes public with 81-qubit protein modeling
All together now: ‘It’s quantum, innit?’
http://www.theregister.co.uk/2012/08/22/d_wave_claims_working_protein_solution_on_quantum_computer/
D-Wave – whose claims to have a working quantum computer have been met with skepticism and major contracts in equal measure – has published a paper in Nature in which it demonstrates the application of quantum annealing to protein folding analysis.
Protein folding is a difficult problem in the classical world, because of the vast number of possible solutions. As D-Wave’s authors put it in their paper (online in full here): “Finding low-energy threedimensional structures is an intractable problem even in the simplest model, the Hydrophobic-Polar (HP) model.”
http://www.nature.com/srep/2012/120813/srep00571/full/srep00571.html
D-Wave’s paper claims to demonstrate the first application of quantum principles to solving protein folding. It’s only been performed on a small scale – using 81 qubits – and is intended as a benchmark.
Moreover, the authors state that the scale of the problem they’ve demonstrated would still be solvable using a classical computer.
“This study provides a proof-of-principle that optimization of biophysical problems such as protein folding can be studied using quantum mechanical devices,” the authors write.
Boffins receive quantum key from moving plane
Alice and Bob play catch
http://www.theregister.co.uk/2012/09/17/qkd_from_moving_airplane/
A group of German researchers has taken a step closer to achieving quantum key distribution with satellites, receiving quantum keys transmitted by a moving airplane.
The experiment is described in this paper (PDF) presented to the QCrypt conference in Singapore last week.
Led by Sebastian Nauerth at the Ludwig Maximilian University of Munich, the researchers achieved a stable connection over 20 Km for ten minutes, and in that time achieved a key rate of 145 bits/s. While that’s far too slow for a data channel, this only refers to the rate at which the keys are transmitted.
Australian researchers create world’s first working quantum bit
Another step taken towards the development of ultra-powerful computers
http://www.cio.com.au/article/436933/australian_researchers_create_world_first_working_quantum_bit/#closeme
Researchers at the University of New South Wales have created the world’s first working quantum bit based on a single atom in silicon, which they claim will lead to the development of ultra-powerful computers in the future.
In a paper published in scientific journal Nature, the research team described how it was able to both read and write information using the spin, or magnetic orientation, of an electron bound to a single phosphorous atom embedded in a silicon chip.
This enabled them to form a quantum bit or “qubit”, the basic unit of data for quantum computers, which promise to solve complex problems “that are currently impossible on even the world’s largest supercomputers,” according to team leader Dr Andrea Morello.
“These include data-intensive problems, such as cracking modern encryption codes, searching databases and modelling biological molecules and drugs.”
“Your co-workers who keep using Schrödinger’s cat metaphor may need to find a new one. New Scientist reports that “by making constant but weak measurements of a quantum system, physicists have managed to probe a delicate quantum state without destroying it”
Source: http://science.slashdot.org/story/12/10/04/010223/quantum-measurements-leave-schrdingers-cat-alive
Quantum computer boffin ‘had to sit down’ on getting Nobel Prize call
Deserved glory, trouserfuls of cash for French/US pair
http://www.theregister.co.uk/2012/10/09/nobel_physics_prize_2012/
The Nobel Prize for physics has gone to French and US boffins for their work quantum manipulation.
Serge Haroche of Collège de France and David Wineland at the National Institute of Standards and Technology in the University of Colorado will share the prize and the £744,000 winnings that go with it for work on single photons and ions.
The Nobel committee said that the pair won for “ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems”.
The scientists’ work has helped build laser-cooled atomic clocks and is a building block for the current research in quantum computing.
“Their work demonstrates very fundamental behaviour of quantum systems under complete control, and underpins quantum technologies relevant to quantum computing and atomic clocks.”
What are quantum computers good for?
Forget cracking crypto, think modelling reality itself to help build a better one
http://www.theregister.co.uk/2012/11/17/how_to_build_and_use_a_quantum_computer/
The problem with trying to explain quantum computing to the public is that you end up either simplifying the story so far as to make it wrong, or running down so many metaphorical rabbit-burrows that you end up wrong.
So The Register is going to try and invert the usual approach, and try to describe quantum computing at a more materialistic level: how do you build one, and when it’s built, how do you use it? Hopefully, a concrete framework will make it easier to understand quantum computing along the way.
And we promise not to reiterate the story of Schroedinger ‘s cat. Not even once.
Researchers achieve mathematical breakthrough that could lead to actual teleportation
http://www2.electronicproducts.com/Researchers_achieve_mathematical_breakthrough_that_could_lead_to_actual_teleportation-article-fajb_math_quantum_physics_jan2013-html.aspx
Protocol sets rules for effective transport of quantum information instantaneously
For the last decade, theoretical physicists have been working to prove that the intense connections between particles as established in the quantum law of “entanglement” could be used as a more effective way to teleport quantum bits of information.
Recently, researchers from Cambridge University published a mathematical solution in which they worked out how entanglement could be “recycled” to increase the efficiency of these connections, and demonstrating a new protocol that could open the door to several potential applications.
You see, entanglement involves two particles (e.g. electrons, protons, etc.) that are intrinsically bound together and retain synchronization whether they’re next to one another or on opposite sides of the globe. Using this connection, quantum bits of information can be relayed instantaneously using traditional forms of communication.
Under this theory, two teleportation protocols were developed: one that could send scrambled information that required correction by the receiver, or a bit more recently, “port-based” teleportation that doesn’t require the correcting of information by the receiver, but rather a ridiculous amount of entanglement, so much so that each object sent would destroy the entangled state.
Quantum computer one step closer after ‘true’ quantum calculation
Baby steps
http://www.theregister.co.uk/2013/02/25/quantum_calculation_phase_estimation/
An international group of physicists has had an important “first” acknowledged by the journal Nature Photonics: they built the first complete single-qubit system to implement a key algorithm in quantum computing.
While prior experiments have demonstrated that the quantum states produced in a phase estimation could be read out, what the Nature: Photonics publication recognises is that this experiment runs the whole process: input, processing, and output.
As the researchers write in their paper: “all demonstrations to date have required already knowing the answer to construct the algorithm.”
Quantum Cryptography Secures the Electrical Grid
http://www.designnews.com/author.asp?section_id=1386&doc_id=261288&cid=NL_Newsletters+-+DN+Daily
the intricacy of renewable energy requires sophisticated methods of grid operation for both energy management and security applications.
To safeguard the grid’s management system, scientists hope to employ the latest encrypted data security measure — quantum cryptography.
A team of researchers at the Los Alamos National Laboratory has successfully demonstrated the use of the new technology to safeguard data transmission.
The new technology is based on a recently developed Quantum Cryptography transmitter that supports the advance security measure at a low latency of 120 ms for every 125 km distances. The researchers hope to help energy providers detect any unwanted tampering to the grid’s energy supply, especially with the added complexity of renewable energy management. The team is now in search of funding for a next-gen transmitter designed for mass production.
Spooky action at a distance is faster than light
Chinese boffins put the clock on information transfer between entangled particles
http://www.theregister.co.uk/2013/04/08/chinese_entanglement_transfer_experiment/
As Einstein put it, it’s impossible for anything – even information – to move faster than the speed of light. Yet the lower bound of that impossibility, the minimum speed at which entanglement can’t possibly be transmitting information between two particles, appears to be around four orders of magnitude higher than c, the speed of light in a vacuum.
So: since we know that entanglement exists (it’s been observed and is the basis of so-called “quantum teleportation”), it’s perfectly reasonable to ask at what rate the information transfer is violating general relativity?
According to this paper at Arxiv, once Earth’s inertial frame of reference is taken into account, the lower bound of the speed of “spooky action” is 1.38 x 104 the speed of light in a vacuum.
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D-Wave wins the quantum-classical horse race, kind of
For the right problem, quantum computing wins
http://www.theregister.co.uk/2013/05/15/d_wave_quantum_computer_test/
It’s official, it seems: the D-Wave isn’t a “real” quantum computer, but it does handle some classes of problems a lot faster than a classical desktop computer.
That’s the result of the first attempt to benchmark the company’s adibiatic quantum computer, but it comes with caveats.
The company says its D-Wave Two offers a “512-qubit processor chip … housed inside a cryogenics system within a 10 square meter shielded room.”
The company doesn’t claim to have a fully quantum computer, but instead to have designed and manufactured “processors required to use quantum effects to compute”.
In a paper to be presented to the ACM conference in Italy on May 15 and published in the New York Times, McGeoch tests the adibiatic quantum computation technique called quantum annealing against various solvers running on desktop computers.
McGeoch compared these two approaches to three software solvers: IBM’s CPLEX, the open-source METSlib tabu search solver, and the Akmaxsat solver.
However, the test result – particularly the QUBO test – are being taken as evidence that something quantum-like is happening in the D-Wave, since it converged on the solution almost instantly compared to the classical computer. So it seems that with the right problem – in particular, a problem that maps well onto the quantum hardware – entanglement and superposition are happening.
For D-Wave, the challenge will be to “generalise” its hardware so as not to be confined only to esoteric problems.
Google Buys a Quantum Computer
http://bits.blogs.nytimes.com/2013/05/16/google-buys-a-quantum-computer/
Google and NASA are forming a laboratory to study artificial intelligence by means of computers that use the unusual properties of quantum physics. Their quantum computer, which performs complex calculations thousands of times faster than existing supercomputers, is expected to be in active use in the third quarter of this year.
The Quantum Artificial Intelligence Lab, as the entity is called, will focus on machine learning, which is the way computers take note of patterns of information to improve their outputs. Personalized Internet search and predictions of traffic congestion based on GPS data are examples of machine learning. The field is particularly important for things like facial or voice recognition, biological behavior, or the management of very large and complex systems.
Google said it had already devised machine-learning algorithms that work inside the quantum computer, which is made by D-Wave Systems of Burnaby, British Columbia. One could quickly recognize information, saving power on mobile devices, while another was successful at sorting out bad or mislabeled data. The most effective methods for using quantum computation, Google said, involved combining the advanced machines with its clouds of traditional computers.
“The tougher, more complex ones had better performance,” said Colin Williams, D-Wave’s director of business development. “For most problems, it was 11,000 times faster, but in the more difficult 50 percent, it was 33,000 times faster. In the top 25 percent, it was 50,000 times faster.”
The machine Google and NASA will use makes use of the interactions of 512 quantum bits, or qubits, to determine optimization. They plan to upgrade the machine to 2,048 qubits when this becomes available, probably within the next year or two.
Google did not say how it might deploy a quantum computer into its existing global network of computer-intensive data centers, which are among the world’s largest. D-Wave, however, intends eventually for its quantum machine to hook into cloud computing systems, doing the exceptionally hard problems that can then be finished off by regular servers.
Launching the Quantum Artificial Intelligence Lab
http://googleresearch.blogspot.fi/2013/05/launching-quantum-artificial.html
We believe quantum computing may help solve some of the most challenging computer science problems, particularly in machine learning. Machine learning is all about building better models of the world to make more accurate predictions. If we want to cure diseases, we need better models of how they develop. If we want to create effective environmental policies, we need better models of what’s happening to our climate. And if we want to build a more useful search engine, we need to better understand spoken questions and what’s on the web so you get the best answer.
So today we’re launching the Quantum Artificial Intelligence Lab. NASA’s Ames Research Center will host the lab, which will house a quantum computer from D-Wave Systems, and the USRA (Universities Space Research Association) will invite researchers from around the world to share time on it. Our goal: to study how quantum computing might advance machine learning.
Machine learning is highly difficult. It’s what mathematicians call an “NP-hard” problem. That’s because building a good model is really a creative act.
Classical computers aren’t well suited to these types of creative problems. Solving such problems can be imagined as trying to find the lowest point on a surface covered in hills and valleys.
That’s where quantum computing comes in. It lets you cheat a little, giving you some chance to “tunnel” through a ridge to see if there’s a lower valley hidden beyond it. This gives you a much better shot at finding the true lowest point — the optimal solution.
We’ve already developed some quantum machine learning algorithms. One produces very compact, efficient recognizers — very useful when you’re short on power, as on a mobile device.
Nasa buys into ‘quantum’ computer
http://www.bbc.co.uk/news/science-environment-22554494
A $15m computer that uses “quantum physics” effects to boost its speed is to be installed at a Nasa facility.
It will be shared by Google, Nasa, and other scientists, providing access to a machine said to be up to 3,600 times faster than conventional computers.
Unlike standard machines, the D-Wave Two processor appears to make use of an effect called quantum tunnelling.
This allows it to reach solutions to certain types of mathematical problems in fractions of a second.
Effectively, it can try all possible solutions at the same time and then select the best.
Google wants to use the facility at Nasa’s Ames Research Center in California to find out how quantum computing might advance techniques of machine learning and artificial intelligence, including voice recognition.
Canadian company D-Wave Systems, which makes the machine, has drawn scepticism over the years from quantum computing experts around the world.
Until research outlined earlier this year, some even suggested its machines showed no evidence of using specifically quantum effects.
But physicists have repeatedly found that the problem with a gate-based approach is keeping the quantum bits, or qubits (the basic units of quantum information), in their quantum state.
“You get drop out… decoherence, where the qubits lapse into being simple 1s and 0s instead of the entangled quantum states you need. Errors creep in,”
Instead, D-Wave Systems has been focused on building machines that exploit a technique called quantum annealing – a way of distilling the optimal mathematical solutions from all the possibilities.
Annealing is made possible by an effect in physics known as quantum tunnelling, which can endow each qubit with an awareness of every other one.
“The gate model… is the single worst thing that ever happened to quantum computing”, Geordie Rose, chief technology officer for D-Wave, told BBC Radio 4’s Material World programme.
Dr Rose’s approach entails a completely different way of posing your question, and it only works for certain questions.
Physicists Create Quantum Link Between Photons That Don’t Exist At the Same Time
http://science.slashdot.org/story/13/05/22/2343208/physicists-create-quantum-link-between-photons-that-dont-exist-at-the-same-time
“Physicists have long known that quantum mechanics allows for a subtle connection between quantum particles called entanglement, in which measuring one particle can instantly set the otherwise uncertain condition, or ’state,’ of another particle—even if it’s light years away. Now, experimenters in Israel have shown that they can entangle two photons that don’t even exist at the same time.”
Physicists Create Quantum Link Between Photons That Don’t Exist at the Same Time
http://news.sciencemag.org/sciencenow/2013/05/physicists-create-quantum-link-b.html?ref=hp
Now they’re just messing with us. Physicists have long known that quantum mechanics allows for a subtle connection between quantum particles called entanglement, in which measuring one particle can instantly set the otherwise uncertain condition, or “state,” of another particle—even if it’s light years away. Now, experimenters in Israel have shown that they can entangle two photons that don’t even exist at the same time.
Entanglement is a kind of order that lurks within the uncertainty of quantum theory.
Entanglement can come in if you have two photons. Each can be put into the uncertain vertical-and-horizontal state. However, the photons can be entangled so that their polarizations are correlated even while they remain undetermined.
For example, if you measure the first photon and find it horizontally polarized, you’ll know that the other photon has instantaneously collapsed into the vertical state and vice versa—no matter how far away it is. Because the collapse happens instantly, Albert Einstein dubbed the effect “spooky action at a distance.”
In recent years, physicists have played with the timing in the scheme.
And even though photons 1 and 4 never coexist, the measurements show that their polarizations still end up entangled.
So what’s the advance good for? Physicists hope to create quantum networks in which protocols like entanglement swapping are used to create quantum links among distant users and transmit uncrackable (but slower than light) secret communications.