Category Archives: Quantum Computer
What is quantum computer? – Definition from WhatIs.com
A quantum computer is a machine, as-yet hypothetical, that performs calculations based on the behavior of particles at the sub-atomic level. Such a computer will be, if it is ever developed, capable of executing far more millions of instructions per second (MIPS) than any previous computer. Such an exponential advance in processing capability would be due to the fact that the data units in a quantum computer, unlike those in a binary computer, can exist in more than one state at a time. In a sense, the machine "thinks" several "thoughts" simultaneously, each "thought" being independent of the others even though they all arise from the same set of particles.
Engineers have coined the term qubit (pronounced KYEW-bit) to denote the fundamental data unit in a quantum computer. A qubit is essentially a bit (binary digit) that can take on several, or many, values simultaneously. The theory behind this is as bizarre as the theory of quantum mechanics, in which individual particles appear to exist in multiple locations. One way to think of how a qubit can exist in multiple states is to imagine it as having two or more aspects or dimensions, each of which can be high (logic 1) or low (logic 0). Thus if a qubit has two aspects, it can have four simultaneous, independent states (00, 01, 10, and 11); if it has three aspects, there are eight possible states, binary 000 through 111, and so on.
Quantum computers might prove especially useful in the following applications:
The main difficulty that the research-and-development engineers have encountered is the fact that it is extremely difficult to get particles to behave in the proper way for a significant length of time. The slightest disturbance will cause the machine to cease working in quantum fashion and revert to "single-thought" mode like a conventional computer. Stray electromagnetic fields, physical movement, or a tiny electrical discharge can disrupt the process.
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What is quantum computer? - Definition from WhatIs.com
Finns chill out quantum computers with qubit refrigerator to cut out errors – ZDNet
This one centimeter-sized silicon chip can help to cool down quantum bits.
Quantum computing is a revolutionary technology, but the obstacles to creating viable quantum computers remain significant.
Chipping away at the task is a team of Finnish researchers, who have found a way to cool down quantum bits, or qubits, using a quantum-circuit refrigerator.
"To my understanding, no one else has done a standalone component that can refrigerate a quantum system," Mikko Mttnen, quantum physicist and research team leader at Aalto University, tells ZDNet.
The significance of this development comes down to the fickle nature of qubits. Unlike in traditional computing, where electronic bits are set to a value of zero or one, qubits can simultaneously hold values of zero, one, or both. Consequently, they can carry out more computations in parallel and solve complex big-data problems much faster than today's systems.
But qubits are very sensitive to external perturbations and need to be well isolated, and that isolation can in turn cause them to heat up and result in calculation errors.
Furthermore, every qubit needs to be reset to its low-temperature ground state at the beginning of a computation. If qubits get too hot, they keep switching between different states.
This is where the cooling mechanism of the Finnish research team comes in. Their system works by tunneling single electrons through a 2nm-thick insulator.
By giving the electrons slightly less energy than that required for tunneling, they instead capture the missing energy from the nearby quantum device, which in turn loses energy and cools down.
This approach means most electrical quantum devices, including computers, could be initialised quickly and made more reliable.
So far, the system has been tested by postdoctoral researcher Kuan Yan Tan with qubit-like superconducting resonators, with the results published in scientific journal Nature Communications.
"In the experiments we did with the resonator, the temperature of the resonator we achieved was too high for quantum computer operations. So we have to show we can cool down to even lower temperatures," Mttnen explains.
In addition to this goal, the next steps for the team will be to test the system with actual quantum bits and make its on-off switch faster.
Mttnen estimates that viable practical applications could be possible in a few years' time, but says it is too early to speculate when these applications could turn into commercial products.
Mttnen's team is only one of the many companies and research organisations working on quantum computing, including tech giants Google, IBM and Microsoft. Despite all these efforts, Mttnen remains cautious when pressed about when the world will finally see the first commercial quantum computer.
"It's almost impossible at this stage to say when. But what I can say is it's more likely we will get there at some point than that we don't," Mttnen says.
US Energy Department lab bolsters quantum computing resources
Researchers at the Oak Ridge National Laboratory are getting cloud access to a D-Wave 2000Q system, allowing them to explore hybrid computing architectures.
Microsoft deepens University of Sydney quantum research partnership
Microsoft has beefed up its efforts to commercialise quantum computing, giving the university funding for new equipment, staff, and talent, as researchers delve deeper into the underlying technology.
Accenture, 1QBit partner for drug discovery through quantum computing
Accenture and quantum computing startup 1QBit have partnered with pharmaceutical giant Biogen to develop a quantum-enabled molecular comparison application for drug discovery.
IBM aims to commercialize quantum computing, launches API, SDK and sees Q systems in next few years
IBM put some more meat on its roadmap and plans to commercialize quantum computing for enterprises. For now, developers will get APIs and a software developer kit to play with qubits.
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Finns chill out quantum computers with qubit refrigerator to cut out errors - ZDNet
Hype and cash are muddying public understanding of quantum computing – The Conversation AU
Its no surprise that quantum computing has become a media obsession. A functional and useful quantum computer would represent one of the centurys most profound technical achievements.
For researchers like me, the excitement is welcome, but some claims appearing in popular outlets can be baffling.
A recent infusion of cash and attention from the tech giants has woken the interest of analysts, who are now eager to proclaim a breakthrough moment in the development of this extraordinary technology.
Quantum computing is described as just around the corner, simply awaiting the engineering prowess and entrepreneurial spirit of the tech sector to realise its full potential.
Whats the truth? Are we really just a few years away from having quantum computers that can break all online security systems? Now that the technology giants are engaged, do we sit back and wait for them to deliver? Is it now all just engineering?
Quantum computers are machines that use the rules of quantum physics in other words, the physics of very small things to encode and process information in new ways.
They exploit the unusual physics we find on these tiny scales, physics that defies our daily experience, in order to solve problems that are exceptionally challenging for classical computers. Dont just think of quantum computers as faster versions of todays computers think of them as computers that function in a totally new way. The two are as different as an abacus and a PC.
They can (in principle) solve hard, high-impact questions in fields such as codebreaking, search, chemistry and physics.
Read More: Quantum computers could crack existing codes but create others much harder to break
Chief among these is factoring: finding the two prime numbers, divisible only by one and themselves, which when multiplied together reach a target number. For instance, the prime factors of 15 are 3 and 5.
As simple as it looks, when the number to be factored becomes large, say 1,000 digits long, the problem is effectively impossible for a classical computer. The fact that this problem is so hard for any conventional computer is how we secure most internet communications, such as through public-key encryption.
Some quantum computers are known to perform factoring exponentially faster than any classical supercomputer. But competing with a supercomputer will still require a pretty sizeable quantum computer.
Quantum computing began as a unique discipline in the late 1990s when the US government, aware of the newly discovered potential of these machines for codebreaking, began investing in university research
The field drew together teams from all over the world, including Australia, where we now have two Centres of Excellence in quantum technology (the author is part of of the Centre of Excellence for Engineered Quantum Systems).
But the academic focus is now shifting, in part, to industry.
IBM has long had a basic research program in the field. It was recently joined by Google, who invested in a University of California team, and Microsoft, which has partnered with academics globally, including the University of Sydney.
Seemingly smelling blood in the water, Silicon Valley venture capitalists also recently began investing in new startups working to build quantum computers.
The media has mistakenly seen the entry of commercial players as the genesis of recent technological acceleration, rather than a response to these advances.
So now we find a variety of competing claims about the state of the art in the field, where the field is going, and who will get to the end goal a large-scale quantum computer first.
Conventional computer microprocessors can have more than one billion fundamental logic elements, known as transistors. In quantum systems, the fundamental quantum logic units are known as qubits, and for now, they mostly number in the range of a dozen.
Such devices are exceptionally exciting to researchers and represent huge progress, but they are little more than toys from a practical perspective. They are not near whats required for factoring or any other application theyre too small and suffer too many errors, despite what the frantic headlines may promise.
For instance, its not even easy to answer the question of which system has the best qubits right now.
Consider the two dominant technologies. Teams using trapped ions have qubits that are resistant to errors, but relatively slow. Teams using superconducting qubits (including IBM and Google) have relatively error-prone qubits that are much faster, and may be easier to replicate in the near term.
Which is better? Theres no straightforward answer. A quantum computer with many qubits that suffer from lots of errors is not necessarily more useful than a very small machine with very stable qubits.
Because quantum computers can also take different forms (general purpose versus tailored to one application), we cant even reach agreement on which system currently has the greatest set of capabilities.
Similarly, theres now seemingly endless competition over simplified metrics such as the number of qubits. Five, 16, soon 49! The question of whether a quantum computer is useful is defined by much more than this.
Theres been a media focus lately on achieving quantum supremacy. This is the point where a quantum computer outperforms its best classical counterpart, and reaching this would absolutely mark an important conceptual advance in quantum computing.
But dont confuse quantum supremacy with utility.
Some quantum computer researchers are seeking to devise slightly arcane problems that might allow quantum supremacy to be reached with, say, 50-100 qubits numbers reachable within the next several years.
Achieving quantum supremacy does not mean either that those machines will be useful, or that the path to large-scale machines will become clear.
Moreover, we still need to figure out how to deal with errors. Classical computers rarely suffer hardware faults the blue screen of death generally comes from software bugs, rather than hardware failures. The likelihood of hardware failure is usually less than something like one in a billion-quadrillion, or 10-24 in scientific notation.
The best quantum computer hardware, on the other hand, typically achieves only about one in 10,000, or 10-4. Thats 20 orders of magnitude worse.
Were seeing a slow creep up in the number of qubits in the most advanced systems, and clever scientists are thinking about problems that might be usefully addressed with small quantum computers containing just a few hundred qubits.
But we still face many fundamental questions about how to build, operate or even validate the performance of the large-scale systems we sometimes hear are just around the corner.
Read More: Compute this: the quantum future is crystal clear
As an example, if we built a fully error-corrected quantum computer at the scale of the millions of qubits required for useful factoring, as far as we can tell, it would represent a totally new state of matter. Thats pretty fundamental.
At this stage, theres no clear path to the millions of error-corrected qubits we believe are required to build a useful factoring machine. Current global efforts (in which this author is a participant) are seeking to build just one error-corrected qubit to be delivered about five years from now.
At the end of the day, none of the teams mentioned above are likely to build a useful quantum computer in 2017 or 2018. But that shouldnt cause concern when there are so many exciting questions to answer along the way.
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Hype and cash are muddying public understanding of quantum computing - The Conversation AU
UNSW joins with government and business to keep quantum computing technology in Australia – The Australian Financial Review
Governments, business and universities have joined forces to keep UNSW's world leading quantum computing technology in Australia, launching a new $83 million company which aims to produce a working prototype computer within five years.
The company, Silicon Quantum Computing Pty Ltd, will have a key goal of retaining IP in Australia and boosting new industries based around quantum computing and other quantum spin-offs.
Establishing the company has been a long-term goal of UNSW physics professor Michelle Simmons who leads the university's research and development in the race to build the world's first practical quantum computer.
Professor Simmons said she approached the federal government to urge public investment in quantum computing because of the many approaches she was getting from large multinationals and overseas venture capital for access to the discoveries her team had made.
Pick us off
"We had lots of different groupings come to us saying they would work with our research teams, but they would have got all the benefits," she said.
"Everything we did would have gone to them. People were trying to pick us off.
"Personally I just felt complete responsibility for just not dropping the ball, making sure that this great thing that we had was not just siphoned off for free."
Professor Simmons said it was an "eye-opener" for her that not only the IT industry was beating a path to her door, but companies from "across the board" illustrating her belief that quantum computing will have a revolutionary impact in many industries including finance, resource extraction, health, pharmaceuticals, logistics and data.
Quantum computers are expected to solve some types of problems millions of times faster than conventional computers.
The new company will hold the quantum computing related patents from the Centre of Excellence for Quantum Computation and Communication Technology, led by Professor Simmons, which also includes researchers from the University of Melbourne and other universities.
Its aim will be to ensure that the full range of industries developed from quantum computing including hardware, software, and big quantum server farms are developed in Australia.
Silicon Quantum Computing's chair, lawyer Stephen Menzies, said the company would not offer exclusive rights on its technology but would only offer licences for specific purposes for a limited time.
"Too much Australian research innovation is lost [overseas]," he said.
Mr Menzies said it was a commercial venture, and its shareholders the federal and NSW governments, Telstra, the Commonwealth Bank of Australia and UNSW would profit from the increasing value of the company's patents.
The company's $83 million capital comes from UNSW ($25 million), the federal government ($25 million), the Commonwealth Bank ($14 million), Telstra ($10 million) plus a new investment of $8.7 million from the NSW government the first to be made from its $26 million quantum computing fund announced last month.
It will fund a major expansion of the quantum computing research effort at UNSW. Up to 40 new staff will be hired including 25 researchers and 12 PhD students, and new equipment to speed the development of a 10 qubit prototype computer by 2022.
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UNSW joins with government and business to keep quantum computing technology in Australia - The Australian Financial Review
‘Tools of DESTRUCTION’ Quantum computers WILL wreak havoc … – Express.co.uk
Quantum computers are the next generation of computers which can operate thousands of times faster than standard machines and process multiple data at once.
The lightning-fast computers allow for multiple questions to be answered at once at a rapid pace, as opposed to standard computers which work through answers sequentially.
While a standard computer uses bits to process problems and information, quantum computers use qubits which can store and process multiple bits of information at the same time.
Alexander Lvovsky, Quantum Optics group leader at the Russian Quantum Center and Professor of Physics at the University of Calgary in Canada, said warned quantum computers will wreak havoc, according to Futurism.
This is because they would be able to break modern cryptography raising fears of major security breaches.
All sensitive digital information that is sent over the internet, such as top secret military information, medical records and financial information, is encrypted to protect the data from hackers.
Some hackers are already able to break encryption, but when hackers get their hands on quantum computers, they will be able to smash any code putting all sensitive information at risk.
Wenjamin Rosenfeld, a physics professor at the Ludwig Maximilian University of Munich, told Futurism: In a sense, Lvovsky's right. Taking a quantum computer as a computer, theres basically not much you can do with this at the moment.
Commercial quantum computers will be available within five years, and other experts believe that this will be enough time to add more protection to the sensitive information and keep it out of reach of hackers.
Mikhail Lukin, a co-founder of the Russian Quantum Center and head of the Lukin Group of the Quantum Optics Laboratory at Harvard University, said: Im fairly convinced that, before quantum computers start breaking encryption, we will have new classical encryption, we will have new schemes based on quantum computers, based on quantum cryptography, which will be operational.
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'Tools of DESTRUCTION' Quantum computers WILL wreak havoc ... - Express.co.uk
Quantum computing comes of age – Alphr
Quantum computing has come a long way since its theoretical birth in the 1980s, with the works of Paul Benioff, Yuri Manin, Richard Feynman and David Deutsch. We still dont have functional, large-scale, universal quantum computers, but it might not be too much longer before we do.
Currently the domain of large companies such as IBM and Google, and physics research labs in universities, the search is on to find the best approach to building one. Leaving aside the work of Canadian company D-Wave Systems, which uses quantum tunnelling effects to solve problems, the two most successful methods for performing quantum computations are through the use of superconductors and trapped ions.
Superconducting computers make use of a Josephson junction: two superconducting electrodes with a barrier down the middle, which exhibits quantum effects when cooled to near absolute zero. Trapped-ion computers, on the other hand, suspend charged particles in magnetic fields to create their quantum gates and induce the desired effects.
These quantum effects include being able to enter a superposition of states. A silicon computer bit can be on or off (0 or 1), but a quantum bit, or qubit, can be 0, 1 or both at the same time. Its mind-blowing, but it works, and when fed the right algorithm it could achieve in an afternoon what it might take a classical supercomputer a billion years to compute.
Thats pretty revolutionary, and the term quantum supremacy was introduced by Caltechs John Preskill to mark the moment quantum computers will exceed the processing power of conventional silicon. That point comes when we have a processor operating at around the 45-50 qubit mark, and some pretty big names think it might be approaching fast.
Earlier this year, Google announced it was planning to run a 50-qubit computer by the end of 2017, and IBM has plans to hit that mark soon too. Its latest machine, a superconducting model weighing in at 17 qubits, is still in the lab, but a five-qubit machine is running and available to the public, with a 16-qubit computer in beta testing. The IBM Quantum Experience has more than 50,000 users who have executed code more than 300,000 times, publishing their results in 17 scientific publications. Theres even an API and code on GitHub to help you get started.
Something you need to keep in mind is they should be perfect qubits, says Dr Stefan Filipp, a quantum computing scientist at IBMs research facility in Zurich, Switzerland. Thats qubits without any influence from the environment, without any noise properties. Theres a grey zone around how many qubits you need to outperform classical computers, but 50 qubits is the first threshold. What we want to make is a universal quantum computer, and that requires perfect qubits, but were realistic enough to know that you dont find perfect qubits.
(Above: Dr Stefan Filipp, Credit: IBM Research)
Whats needed is some form of error correction. We know now that if we have 100 or 1,000 imperfect qubits, we can distill from them one perfect qubit. says Filipp. So if you want to have 50 perfect qubits, depending on how imperfect the real ones are, we have an overhead of 1,000 or even more qubits.
Its still the case that we need to build a system thats actually capable of outperforming a classical computer. We are quite certain that we can do this, but its not clear whether this will be this year, next year or in five years.
Not everyone sees this model of quantum computer as the best way forward, however. Winfried Hensinger, professor of quantum technologies at the University of Sussex, has published a plan for building a quantum computer today, using existing trapped-ion technology.
Trapped ions are a very attractive candidate [for quantum computing] because they can work at room temperature, he says. To solve really interesting problems, you need millions or billions of qubits, so imagine being able to cool all those quantum bits down to such a low temperature. Were talking 0.01K, or -273C, remember.
The method to implement quantum gates with trapped ions has been to use pairs of laser beams, Hensinger explains. They have to be focused to a precision of one-hundredth of the width of a human hair. That can be easily done if you have only a few ions, but imagine you want to build a quantum computer with millions and billions of qubits. The engineering requires you to have millions and billions of laser beams.
Weve been thinking about this for a long time, and developed an entirely different approach involving applying voltage to a microchip to do exactly the same thing. We can now replace millions and billions of laser beams with voltages. In a way its exactly how a classical computer works the transistors in a microprocessor work the same way. You apply a voltage, and that executes logical operations.
(Above: Prof Winfried Hensinger, Credit: University of Sussex)
Sad as we are to see the back of quite so many lasers, at least the finished computer might be impressively large. A quantum computer, because of the way it operates, cant be very small because its unbelievably complicated to isolate the ions in such a way that the quantum effects arent being destroyed by things around them, and thats where you get headlines about computers the size of football pitches, says Hensinger. The machine will need to be modular, with many smaller processors linked together using another innovation connectivity using electrical fields, a sort of incredibly fast quantum Bluetooth. We could start building it today, but it could still take ten years to build a large machine.
Yet even if such a machine were built, what would we do with it? IBMs Quantum Experience has seen experiments geared toward figuring out what works on a quantum computer and how you write an algorithm for it. In the future, we could see applications in quantum chemistry, as Filipp explains: To describe an electron system, you need two complex numbers. For 100 electrons you need 2100 such numbers, and it would take all the data storage available at the moment to even store these. But a quantum computer can handle it, because you dont have to store this information in a bitstream, but in real physical objects. And these quantum objects are described by quantum mechanics, so they have these numbers already intrinsically in them.
Hensinger has a slightly different view. A quantum computer isnt a fast conventional computer, he says. One interpretation of how it works is it makes use of computations across parallel universes and you can already see how mind-bending that is.
It can solve certain problems in maybe a few hours that even the fastest supercomputer in the world would take billions of years to calculate. At the moment an example is breaking encryption, but for every problem you want to solve, you need to write a new algorithm that makes use of this strange ability to do things in multiple parallel universes. Were not going to take some software, run it on a quantum computer and it will run very fast. Thats a misconception.
Hensinger draws an analogy with the Colossus computer created by Alan Turing and Tommy Flowers to crack Germanys teleprinter codes during World War II. In terms of conventional computers, quantum computers are right now in the 1940s, he tells me. Were very impressed by them, but we dont yet know what they can do.
And whats run on them needs to be tailored to their abilities. There are about 50 people in the world, at most, writing quantum computer algorithms, says Hensinger. The key problems are those a conventional computer could never solve; it would take forever. Its disruptive technology it can change an entire sector of business by adding capability that was previously not available.
This certainly sounds remarkable, but Hensingers huge machines and Filipps absolute-zero cooling systems dont sound very consumer-friendly. Will we all end up owning one? Filipp isnt sure. I think when we have quantum computers that are capable of replacing a laptop, the cooling requirements will be solved, but its not in the near term that quantum computers will replace desktop or laptop computers, he says. Our vision of a quantum computer can do anything a normal computer can do, in principle, but you wouldnt use it for that because its too complicated at the moment.
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Quantum computing comes of age - Alphr
No, Quantum Teleportation Won’t Let Us Send Instant Messages to Alpha Centauri – Air & Space Magazine
In what sounds like a Beam me up, Scotty moment, Chinese scientists recently teleported the first photons to orbit. But unlike the glowing transporter in Star Trek, teleportation experiments in 2017 still have to follow the laws of physics, which means that instant travel toor even communication withnearby stars wont happen.
The Chinese experiment began last year, when a satellite called Micius (named after an ancient Chinese philosopher) blasted off on top of a Long March rocket. Equipped with a photon receiver, Micius passes over ground stations at the same time every day, during which times scientists can beam up a stream of photons.
Beaming, in this case, doesnt mean the instantaneous transfer of photons from one location to another. Like anything else, these elementary particles can travel no faster than the speed of light. Their ability to carry information relies on a principle called quantum entanglement, which happens when tiny particles (including photons) form at the same time and place. In the weird world of quantum physics, this means the two objects share the same existence (or more technically, have the same wave function).
Even stranger, this shared existence continues even if you separate the photons by centimeters, meters, or kilometers. If you measure one photon, it will affect the state of the other, entangled photon. This principle has been demonstrated several times in labs, over fiber optic cables, and even on airplanes, but never in a space experiment.
The Micius team says their ground-to-space entanglement took place over 500 kilometers, shattering the previous entanglement record (100 kilometers) five-fold. Because atmospheric interference could break the entanglement, the Chinese researchers beamed the entangled photons from a ground station in Tibet located more than 4,000 meters above sea level. The results werent perfect, though; only 911 photons got through to space, out of millions of photons sent.
This is remarkable on many levels: a 500 km distance, the challenges of stabilizing and tracking the satellite, and atmospheric turbulence, said Shellee Dyer, a member of the faint photonics group at the U.S. National Institute of Standards and Technology, in an e-mail. I am not aware of any specific U.S. research that focuses specifically on ground-to-satellite quantum teleportation, [although] there have been experiments demonstrating quantum teleportation and pushing the limits of distance.
Does the research have any application to space travel?
The privately funded Breakthrough Initiative proposes to send a flotilla of tiny spacecraft to Alpha Centauri around 2038, at 15 to 20 percent of the speed of light. Brian Koberlein, an astrophysicist at the Rochester Institute of Technology in New York, points out that even if the nanosatellites carried entangled particles on board, we wouldnt be able to communicate with the spacecraft instantaneously.
You have to send a beam of light to the satellite to entangle with the other one [on the ground], he says. That beam would be limited to the speed of light, and only when you do the measurement [does] the state change instantaneously. You could not decide to send a message now, and get it to Alpha Centauri in less than four years.
While we cant use quantum teleportation to shorten interstellar distances, future quantum computers will almost certainly be used to help solve critical problems related to space travel. NASA is among the many agencies and private companies playing in this technology sector, which has application in fields ranging from aeronautical simulation to computer security and cryptography. We may see the first practical quantum computers coming online within the next few years.
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No, Quantum Teleportation Won't Let Us Send Instant Messages to Alpha Centauri - Air & Space Magazine
Google on track for quantum computer breakthrough by end of …
Ramping up the qubits
Julian Kelly/Google
By Matt Reynolds
Google is leading the pack when it comes to quantum computing. The company is testing a 20-qubit processor its most powerful quantum chip yet and is on target to have a working 49-qubit chip by the end of this year.
Qubits, or quantum bits, can be a mixture of 0 and 1 at the same time, making them potentially more powerful than classical bits.
And if everything goes to plan, the 49-qubit chip will make Google the first to build a quantum computer capable of solving certain problems that are beyond the abilities of ordinary computers. Google set itself this ambitious goal, known as quantum supremacy, in a paper published last July.
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Alan Ho, an engineer in Googles quantum AI lab, revealed the companys progress at a quantum computing conference in Munich, Germany. His team is currently working with a 20-qubit system that has a two-qubit fidelity of 99.5 per cent a measure of how error-prone the processor is, with a higher rating equating to fewer errors.
For quantum supremacy, Google will need to build a 49-qubit system with a two-qubit fidelity of at least 99.7 per cent. Ho is confident his team will deliver this system by the end of this year. Until now, the companys best public effort was a 9-qubit computer built in 2015.
Things really have moved much quicker than I would have expected, says Simon Devitt at Macquarie University in Sydney, Australia. Now that Google and other companies involved in quantum computing have mastered much of the fundamental science behind creating high-quality superconducting qubits, the big challenge facing these firms is scaling these systems and reducing their error rates.
It is important not to get carried away with numbers of qubits, says Michele Reilly, CEO at Turing Inc, a quantum start-up. Its impossible to really harness the power of these machines in a useful way without error correction, she says a technique that mitigates the fickle nature of quantum mechanics.
Ho says it will be 2027 before we have error-corrected quantum computers, so useful devices are still some way off. But if Google can be the first to demonstrate quantum supremacy, showing that qubits really can beat regular computers, it will be a major scientific breakthrough.
Read more: Revealed: Googles plan for quantum computer supremacy
We have corrected the affiliation of Simon Devitt
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Google on track for quantum computer breakthrough by end of ...
Closing In On Quantum Computing | WIRED
For more than two decades, writes Valerie C. Coffey (@StellarEdit), one of the holy grails of physics has been to build a quantum computer that can process certain types of large-scale, very difficult problems exponentially faster than classical computers. Physicists are making progress toward this goal every day, but nearly every part of a quantum computer still needs re-engineering or redesign to make it all work. [The Incremental Quest for Quantum Computing, Photonics Spectra, 6 June 2014]
With companies like Google and Microsoft seriously pursuing the subject of quantum computing, progress towards creating a indisputable quantum computer is likely to speed up. I say an indisputable quantum computer because the Canadian company D-Wave already has a quantum computer on the market; but, scientists are torn over whether it truly operates as a quantum computer. The problem with quantum computing is that you can never look under the hood to see what is going on because such an act would interfere with the quantum magic that allows a particle (in this case, a qubit) to be both a zero and a one at the same time. The following explanatory video calls this a secret computation. If you are new the subject of quantum computing, youll find the video both fascinating and insightful.
As the video notes, one of the challenges associated with quantum computing is instability. Because calculations are taking place at the quantum level, the slightest interference can disrupt the process. To increase stability, most experimental systems rely on heavy shielding and are cooled to operating temperatures approaching absolute zero. Thats makes quantum computers very expensive to build and maintain. Since they are so difficult and expensive to work with, you might ask: Why bother? Paul Lopata, a physicist at the Laboratory for Physical Sciences in College Park, MD, explains, Despite the well-known successes of computing machines based on digital logic, some algorithms continue to be difficult to perform and some problems are intractable not only on existing machines but on any practical digital-logic machine in the foreseeable future! [Beyond digital: A brief introduction to quantum computing, The Next Wave, Volume 20, No. 2, 2013] He continues:
These intractable problems serve as both a curse and a blessing: A curse because solutions to many of these intractable problems have significant scientific and practical interest. A blessing because the computational difficulty of these intractable problems can serve as a safeguard for secure data storage and secure data transmission through the use of modern encryption schemes. It is clear that the only algorithmic way to solve these intractable problems is to utilize a computing machine that is based on something other than standard digital logic. One such path toward developing a beyond-digital logic machine is in the field of quantum computing. Quantum computing is still in the early stages of its development, and most of its advances are being reported from universities and basic research labs.
One of the more interesting advances that has been made resulted from an experiment at Washington State University. Eric Sorensen, a WSU science writer, reports, Researchers at Washington State University have used a super-cold cloud of atoms that behaves like a single atom to see a phenomenon predicted 60 years ago and witnessed only once since. [Discovery opens new path to superfast quantum computing, WSU News, 4 June 2014] The phenomenon to which Sorensen refers is called a Bose-Einstein condensate. Sorensen explains that the condensate is important to the field of quantum computing because it makes it easier for researchers to test assumptions and changes in the atomic realm of quantum physics. The experiment was conducted by Peter Engels and his colleagues, who were able to cool about one million atoms of rubidium to 100 billionths of a degree above absolute zero.
At that point, Sorensen explains, the cluster of atoms formed a Bose-Einstein condensate a rare physical state predicted by Albert Einstein and Indian theorist Satyendra Nath Bose after undergoing a phase change similar to a gas becoming a liquid or a liquid becoming a solid. Once the atoms acted in unison, they could be induced to exhibit coherent superradiant behavior predicted by Princeton University physicist Robert Dicke in 1954. Engels told Sorensen, This large group of atoms does not behave like a bunch of balls in a bucket. It behaves as one big super-atom. Therefore it magnifies the effects of quantum mechanics. Sorensen notes, While their cloud of atoms measures less than half a millimeter across, it is large enough to be photographed and measured. This gives experimenters a key tool for testing assumptions and changes in the atomic realm of quantum physics.
What Sorensen doesnt say is that a Bose-Einstein condensate (BEC) can act as a stable qubit. Coffey notes, The creation and control of a single qubit is inherently difficult, but controlling many of them simultaneously is even harder. Quantum states are fundamentally limited for the same reasons that the number of transistors on a semiconductor board is limited, according to Christopher Monroe, professor of physics at the University of Marylands Joint Quantum Institute in College Park. The more of them you have, the more difficult it is to connect them and the noisier the system. An article from European Grid Infrastructure notes, A BEC is a versatile quantum system that can be precisely controlled, and it is one of the essential requirements for building a quantum computer. [Getting closer to quantum computing with the grid, European Grid Infrastructure, 21 July 2014]
Researchers from the University of Waterloos Institute for Quantum Computing (IQC) agree that one major hurdle in harnessing the power of a universal quantum computer is finding practical ways to control fragile quantum states. In an attempt to address that problem, IQC researchers, Joseph Emerson, Mark Howard, and Joel Wallman, have confirmed theoretically that contextuality is a necessary resource required for achieving the advantages of quantum computation. [Study finds weird magic ingredient for quantum computing, Phys.org, 11 June 2014] The article explains:
Quantum devices are extremely difficult to build because they must operate in an environment that is noise-resistant. The term magic refers to a particular approach to building noise-resistant quantum computers known as magic-state distillation. So-called magic states act as a crucial, but difficult to achieve and maintain, extra ingredient that boosts the power of a quantum device to achieve the improved processing power of a universal quantum computer. By identifying these magic states as contextual, researchers will be able to clarify the trade-offs involved in different approaches to building quantum devices. The results of the study may also help design new algorithms that exploit the special properties of these magic states more fully.
Another interesting breakthrough was announced earlier this year by researchers from Yale University. Scientists at Yale University have demonstrated the ability to track real quantum errors as they occur, a major step in the development of reliable quantum computers. [Major Leap Toward Quantum Computing, PCB 007, 14 July 2014] The article notes that information loss, or quantum error, is a major challenge for quantum computing. Yale physicist Rob Schoelkopf, Sterling Professor of Applied Physics and Physics, stated, Ninety-nine percent of quantum computing will be correcting errors. Demonstrating error correction that actually works is the biggest remaining challenge for building a quantum computer. The article continues:
Schoelkopfs group and other Yale collaborators tackled the first step in quantum error correction successfully identifying errors as they happen, in their case by means of a reporter atom. Identifying quantum-computing errors in real time is particularly challenging: Qubits are so fragile that searching for errors can result in more errors. To determine if an error occurred, Schoelkopf and his team relied on an ancilla, or a more stable reporter atom, which detected errors without destroying the state and relayed that information back to the scientists on a computer. During their experiments, the scientists used a superconducting box containing the ancilla and an unknown number of photons, or light particles, which were cooled to approximately -459F, a fraction of a degree above absolute zero. This minimized quantum errors induced by the environment.
The team then tracked the photons in the box over time to see if and when the photons escaped. Losing photons from the box indicated lost information, or the occurrence of a quantum error. The errors need to be detected without learning the exact conditions in the superconducting box, including the number of photons, because determining the conditions in the box can disrupt the qubit quantum state and result in more errors. So the ancilla reported only the photon parity whether an even or odd number of quantum photons were present in the box in real time. A change in parity for example, from even to odd indicated the loss of a single photon without revealing whether the box had changed from six to five photons or from four to three photons. The team found success in their first experiment and demonstrated for the first time the tracking of naturally occurring errors, in real time, as would be needed for a real quantum computer.
Schoelkopf asserts, It is hard to estimate how long it will be until we have functional quantum computers, but it will be sooner than we think. Thats a claim weve heard before (see my post Quantum Future: Just Beyond Our Grasp). Lets hope that this time the prediction is more accurate.
Stephen F. DeAngelis is President and CEO of the cognitive computing firm Enterra Solutions.
World’s Leading Physicist Says Quantum Computers Are Tools of Destruction, Not Creation – Futurism
Weapon of Mass Disruption
Quantum Computers are heralded as the next step in the evolution of data processing. The future of this technology promises us a tool that can outperform any conventional system, handling more data and at faster speeds than even the most powerful of todays supercomputers.
However, at the present juncture, much of the science dedicated to this field is still focused on the technologys ultimate utilization. We know that quantum computers could manage data at a rate that is remarkable, but exactlywhat kind of data processing will they be good for?
This uncertainty raises some interesting questions about the potential impact of such a theoretically powerful tool.
Last month, some of the leading names in quantum technologies gathered at the semi-annual International Conference on Quantum Technologies in Moscow. Futurism was in attendance and was able to sit and talk with some of these scientists about how their work is moving us closer to practical quantum computers, and what impact such developments will have on society.
One of the most interesting topics of discussion was initiated by Alexander Lvovsky, Quantum Optics group leader at the Russian Quantum Center and Professor of Physics at the University of Calgary in Canada. Speaking at a dinner engagement, Lvovsky stated that quantum computers are a tool of destruction, not creation.
What is it about quantum computers that would incite such a claim? In the end, it comes down to one thing, which happens to be one of the most talked about potential applications for the technology:Breaking modern cryptography.
Today, all sensitive digital information sent over the internet is encrypted in order to protect the privacy of the parties involved. Already, we have seen instances where hackers were able to seize this information by breaking the encryption. According to Lvovsky, the advent of the quantum computer will only make that process easier and faster.
In fact, he asserts that no encryptionexisting today would be able to hide from the processing power of a functioning quantum computer. Medical records, financial information, even the secrets of governments and military organizations would be free for the takingmeaning that the entire world order could be threatened by this technology.
The consensus between other experts is, essentially, that Lvovsky isnt wrong. In a sense, hes right, Wenjamin Rosenfeld, a physics professor at the Ludwig Maximilian University of Munich, stated in an interview. He continued, taking a quantum computer as a computer,theres basically not much you can do with this at the moment; however, he went on to explain that this may soon be changing.
To break this down, there are only two quantum algorithms at the moment, one to allow a quantum computer to search a database, and the other,Shors algorithm, which can be used by a quantum computer to break encryption.
Notably, during the conference, Mikhail Lukin, aco-founder of theRussian Quantum Centerand head of the Lukin Group of the Quantum Optics Laboratory at Harvard University, announced that he had successfully built and tested a 51-qubit quantum computerand hes going to use that computer to launch Shors algorithm.
Vladimir Shalaev, who sits on the International Advisory Board of the Russian Quantum Center and is a professor of Electrical and Computer Engineering at Purdue University, takes a more nuanced approach to this question, saying it is neither a tool of destruction nor creationit is both: I would disagree with him. I think I would say that any new breakthrough breeds both evil and good things.
He evoked the development of laser technology as an example, saying, Lasers changed our lives with communications, surgery, their use in machinery, but they are also used in missiles to destroy buildings.But I think this is life. Nothing comes with only good, there is always bad as well. So I dont think it is just a destructive technology, it could also be a constructive one.
There is a great deal of truth to Shalaevs assessment. Nuclear technology was primarily developed as a destructive tool. After the war, many more positive applications were found, impacting energy, medicine, and agriculture, among many other fields. Quantum computers may not be capable of the physical destruction of a nuclear bomb, but their potential application in relation to encryption is the digital equivalent, making this topic worthy of reflection in these early stages.
So, if quantum computers do have such dangerous potential, why are we pursuing them? As Lukin expounds, there are other potential applications outside of encryption breaking, applications that many experts are excited about.
For example, Lukin sees enormous potential in quantum sensors. It has the potential to change the field of medical diagnostics, where some of the tasks which require huge labs can be performed on the scale of aniPhone. Imagine the implications for third world countries in parts of the world like Africa. It can really allow to diagnose and treat patients. I think theres actually a huge impact on society, he explained.
Also, the processing power of quantum computers could push research in artificial intelligence (AI) forward by leaps and bounds. Indeed, it could assist this field to such a degree that AI could be a part of the answer to the problem proposed by Lvovsky. To that end, Lukins asserts, Im fairly convinced that, before quantum computers start breaking encryption, we will have new classical encryption, we will have new schemes based on quantum computers, based on quantum cryptography, which will be operational.
Much like lasers or nuclear weapons, the scientists involved in creating quantum computers are unable to predict the total utility of this technology. There very well could be a host of world changing applications for quantum computers. Still, even with just considering the encryption busting potential of the technology, we must remain cognizant of the power we areunleashing.
Originally posted here:
World's Leading Physicist Says Quantum Computers Are Tools of Destruction, Not Creation - Futurism