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Supercomputing Hardware

Will Quantum Computing Make It Out of the Lab? 129

Posted by Soulskill
from the those-crafty-rats-did dept.
alphadogg writes "Researchers have been working on quantum systems for more than a decade, in the hopes of developing super-tiny, super-powerful computers. And while there is still plenty of excitement surrounding quantum computing, significant roadblocks are causing some to question whether quantum computing will ever make it out of the lab. 'Artur Ekert, professor of Quantum Physics, Mathematical Institute at the University of Oxford, says physicists today can only control a handful of quantum bits, which is adequate for quantum communication and quantum cryptography, but nothing more. He notes that it will take a few more domesticated qubits to produce quantum repeaters and quantum memories, and even more to protect and correct quantum data. "Add still a few more qubits, and we should be able to run quantum simulations of some quantum phenomena and so forth. But when this process arrives to 'a practical quantum computer' is very much a question of defining what 'a practical quantum computer' really is. The best outcome of our research in this field would be to discover that we cannot build a quantum computer for some very fundamental reason, then maybe we would learn something new and something profound about the laws of nature," Ekert says.'"
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Will Quantum Computing Make It Out of the Lab?

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  • by Anonymous Coward

    *Shakes the magic 8-electron*

    Reply hazy, try again

    • by Anonymous Coward

      *Shakes the magic 8-electron*

      Outcome uncertain, try again

  • With just a few more qubits, I could have entangled first post.

    • What's with those qubits, anyway? Wasn't Noah's ark so many qubits long, so many qubits wide, and some amount of qubits high? WTF? If the quantum computer people are going blblical on us, we may NEVER see a working computer! After all these years, no one is quite certain what the hell a qubit was in the Bible. How are they gonna know what a qubit is inside a computer?

  • Once some lab figures out how to do it it will seem so easy in hindsight.
    • by Mashiki (184564)

      I agree. Though I expect that quantum computers will end up being cost prohibitive to the average consumer. What will end being in consumer electronics is some variant of optical processing.

      • Not just expensive - not that interesting. Quantum computers can't just take algorithms written for classical computers and run them insanely fast, they can run a certain category of algorithm insanely fast. A typical user would be better off with a slightly faster classical computer than an insanely fast quantum computer. For certain applications, a quantum coprocessor might be interesting though,
  • Quantum Computing isn't going to work immediately, it's just life. It's going to make small progressions over time. Eventually there will be advancements that will make them practical for a given purpose. They will follow something like a "Moore's Law" of Quantum computing. Then some intelligent person will utter "I think there is a world market for maybe five Quantum computers"!!!

  • by JoshuaZ (1134087) on Monday September 26, 2011 @02:41PM (#37518490) Homepage

    The current state of the field is advancing. The real problem as discussed in TFA is scaling quantum computers in a useful way that can still do error correction. Shore's algorithm which allows you to quickly factor numbers using a quantum computer requires on the order of n qbits to factor an n bit number. So if one wants to factor say a 300 digit number used in some public key crypto system you would need to control around 300 qbits. The technology for that is clearly very far. There's been recent work using superconducting systems and using quantum dots for qbits both of which look more promising than previous systems. (The first experiments were done with NMR systems which are clearly not very scalable).

    From a strictly theoretical compsci perspective, the set of things it seems that quantum computers can do seems to be growing larger. Recent work by Scott Aaronson and others suggest that BQP (the set of problems which can be easily solved by a quantum computer with a low probability of error) may not lie in the polynomial hierarchy at all. http://arxiv.org/abs/0910.4698 [arxiv.org]. This is a much stronger claim then the claim that BQP doesn't lie in NP. This raises the hope that there may be some problems thought of as extremely difficult that lie in NP. However, trying to actually prove any strong results at this point is likely going to be really tough. At this point although many suspect that BPP (the classical analog of BQP) is equal to P, at this point we can't even prove that BPP lies in NP. In many ways theoretical comp sci is still very much in its infancy.

  • Maybe; maybe not.
  • by TheSync (5291) on Monday September 26, 2011 @02:41PM (#37518504) Journal

    1) We have built qbits
    2) We have entangled qbits
    3) We have implemented the CNOT which is the universal gate for quantum computing (similar to NAND/NOR universal gates in classical computing)

    The question is scaling up number of qbits, increasing coherence times (and possibly using coding solutions to reduce decoherence problems).

    We have a number of quantum algorithms [wikipedia.org] waiting to be implemented, and even have quantum programming languages [wikipedia.org] that you can run simulations on at home today. And there is even a LinkedIn Group [linkedin.com] on quantum information science.

    But I must admit that it could end up like fusion. We have all the basic theoretical knowledge of how to do fusion, and we can do a bit of fusion in the lab, what we lack is the engineering knowledge to achieve enough fusion on a large enough scale to make it practical.

    • by cjonslashdot (904508) on Monday September 26, 2011 @02:59PM (#37518728)

      First of all, I must disclose that I cannot speak authoritatively on this. While I know quantum mechanics and nuclear physics, I have never studied the problem of quantum computing. Therefore, take my opinion here on this topic with a grain of salt.

      But I must confess that intuitively, it seems improbable. There is no "free lunch". Computing is a process of creating information. There is no shortcut for that. The primary challenge with quantum computing seems to be about maintaining adequate coherence, and I suspect that that maintaining coherence throughout a calculation will be equivalent in some manner to performing the calculation in a linear manner. But time will tell.

      • by ThorGod (456163)

        I suspect that that maintaining coherence throughout a calculation will be equivalent in some manner to performing the calculation in a linear manner. But time will tell.

        As designed by the Sirius Cybernetics Corporation...all of the fatal flaws are perfectly masked by the superficial flaws?

        • Perhaps! LOL

          But once again, I don't want to assert this with any certainty. Just food for thought. Perhaps I am wrong.

      • (I'm not a physicist, but I have studied some quantum computing.)

        Even though I suspect it's wise to listen to a physicist's intuition on these matters, I think your intuition might have been clouded by the hype surrounding quantum computers. The truth is that there's really no free lunch. Nobody (outside the media) claims that quantum computers instantly solve all kinds of problems.

        Think of it this way: some things in quantum mechanics are very hard to simulate using classical computers (it's much harder th

    • To some extent, I suspect that quantum computing might well end up with the same problem that quantum mechanics is facing now: it works awesomely great on a very, very small scale, but cannot be used to explain the large scale force of gravity. Similarly, quantum computing might very well work with a few dozen to hundred qbits, but will fall apart at a larger scale where the number of error correcting mechanisms required to overcome decoherence will be too much.

    • by Urkki (668283)

      But I must admit that it could end up like fusion. We have all the basic theoretical knowledge of how to do fusion, and we can do a bit of fusion in the lab, what we lack is the engineering knowledge to achieve enough fusion on a large enough scale to make it practical.

      It could also be, that we don't lack just the engineering knowledge, we lack the universe with suitable physical laws... But hopefully not.

    • by ThorGod (456163)

      I remember Feynman wrote some about quantum computing. He always seemed positive on the idea, and I'm inclined to believe him. (That also ends my claimed background on all things quantum computing. From hereon I'm speculating, so there's no sense in flaming a dreamer - for those who might.)

      A quantum computer, though, isn't a fusion reactor. The end goals for both systems are different. In a sense, the requirement that a fusion reactor eventually sustain itself (as it were) is something a quantum computer ne

      • by PaulBu (473180)

        I remember Feynman wrote some about quantum computing. -- Yeah, see, e.g., here: http://www.phy.mtu.edu/~sgowtham/PH4390/Week_02/IJTP_v21_p467_y1982.pdf [mtu.edu]

        Some people say that he coined the term "Quantum computer", others say that he popularized it, and it was originally due to David Deutsch. And of course it was influenced by Fredkin and Toffoli, and others asking about energy requirements for computation. And THAT goes back to von Neumann!

        Now, von Neumann gave us not only classical computer view, currently

    • But I must admit that it could end up like fusion.

      At least for fusion, we know that it should be possible both in theory and practice (just look at the Sun for proof).

    • There has been an exponential increase [quantenblog.net] in the number of qubits under control since the first serious experiments started almost two decades ago. If the current trend continues, we will have usable quantum computers between 2020 and 2023.

    • The real issue is whether it's costs can be brought down and whether it can scale. Quantum computing may stay too expensive for anyone outside of governments and corporations doing serious scientific research. The idea that just because you have quantum bits on one scale, that this scale will continue up as systems get larger is the flaw. You may get scalability but might hit a cost wall. BTW we still don't have flying cars. I use flying cars as an example of drawing a conclusion about the cost of tech

  • The answer is both Yes and No.

    It is a superposition of skates.

    -----
    Google: partner with everyone, sue no one.
    Apple: partner with no one, sue everyone.
  • Let's not forget... (Score:5, Informative)

    by Nethemas the Great (909900) on Monday September 26, 2011 @02:48PM (#37518594)
    the history of the PC. How many decades did it take for us to get where we are? The first PC was some 50 years in the making and by today's standards was downright laughable in its capabilities. The first computers weren't Von Neumann machines either. You had to have a team of dedicated operators reconfigure patch cables between between outputs and inputs for each an every calculation! To be so pessimistic so early in the life of quantum computing is insulting to the progress we've made so far which is considerably outstripping the pace of development of the modern computer.
    • the history of the PC. How many decades did it take for us to get where we are? The first PC was some 50 years in the making and by today's standards was downright laughable in its capabilities. The first computers weren't Von Neumann machines either. You had to have a team of dedicated operators reconfigure patch cables between between outputs and inputs for each an every calculation! To be so pessimistic so early in the life of quantum computing is insulting to the progress we've made so far which is considerably outstripping the pace of development of the modern computer.

      My pessimism is driven by a firm belief there is no free lunch in the universe. There is no perpetual motion. There is no well of infinite computation.

      If you think your going to be able to answer questions requiring classic processors having the mass of the sun with a QC having many thousands of entangled qbits in a single coherent system I *believe* this is fantasy.

      If your bar is much much lower.. say cost effective QC on desktops which add 1k, 1m or a billion times performance for some classes of proble

      • by hedwards (940851)

        Just because it's hyped doesn't mean that it's not real. Granted it's highly unlikely that we'll get unlimited computational power, but that's hardly reason to believe that quantum computing won't ever happen. Keep in mind that if you asked somebody working in a computer lab back in the 60s or even 80s, what we have now would likely be met with a lot of skepticism as well.

        • by Yoik (955095)

          Actually there was an issue of Communications of the ACM on the 25th anniversary of ENIAC (about 1971) that predicted mid 90's microprocessors quite accurately. An IBM 7094 in a wristwatch is the phrase I recall, the brand might be wrong.

          Nobody knew what would happen with components, but the outlines of Moore's law were visible even then.

      • by JoshuaZ (1134087)
        The key issue for quantum computing isn't that it will allow fixed increases in performance by some factor. The key is that it allows asymptotic increases. Thus for example, Shor's algorithm allows you to factor integers at a rate which is asymptotically better than classical factoring algorithms (although we can't actually prove that no better classical algorithm exists. This is a statement that is strictly stronger than claiming that P != NP). This is part of a general pattern. So, as computational power
        • I'm not sure what you were expecting quantum computers to be able to do. There's a lot of media hype which is made worse by people who just don't understand stuff. For example, there's no known way to solve any NP complete problem in polynomial time on a quantum computer. Similarly, while quantum computers can break many public key crypto systems (such as those based on the difficulty of factoring large numbers or on the closely connected problem of the discrete log), they can't break every public key cryptosystem. Quantum computers aren't magic and the people working with them haven't said otherwise.

          I'm expecting computational power to scale to the exponent of the number of entangled qbits. Further I expect the number of qbits in the system to run well into the thousands.

          Without the above you will never see a single code of any consequence broken on a QC.

          2^1000 is a number with more than 300 digits and most certainly qualifies as magic to me.

          There is simply not enough matter on earth available to build a powerful enough computer based on any other known principal.

          In my mind arbitrary scaling of n^qbit

          • by Chris Burke (6130)

            2^1000 is a number with more than 300 digits and most certainly qualifies as magic to me.

            And? You don't need 2^1000 qubits (or bits) to deal with 1000-binary-digit numbers. You need 1000. Your computer right now can easily handle such numbers.

            There is simply not enough matter on earth available to build a powerful enough computer based on any other known principal.

            Powerful enough to do what? Factor 1000 bit numbers? Well that's a problem with classical computers. Not an inherent principle of the universe, because the universe doesn't operate on classical principles.

            In my mind arbitrary scaling of n^qbits is in the same category as denying the conservation of energy. I don't believe in something for nothing. I reject the idea it is possible to extract ungodly amounts of computation from the universe simply because it smacks of something for nothing.

            "Arbitrary" as in unending, no, but there's little reason to think they couldn't be scaled exponentially for as long as we've done the same with tr

          • by JoshuaZ (1134087)
            You don't get information from anything in a quantum computation. The total information is the same. The only substantial difference is that you can process some things faster. This isn't similar to the issue of conservation of energy- in that context there's a mathematical law that you can't break. Here there's just a lot of computation that you can do faster. We already know that this can happen at a small scale, the primary issue is scaling it up which seems to be an engineering problem. We don't know of
    • by hedwards (940851)

      That was more or less my thought, I mean quantum computing is probably a lot further along than when Babbage came up with his difference engine idea. And it wasn't until a century or so after his death that computers finally made their way out of the lab and started winding up in living rooms on a regular basis.

    • by Osgeld (1900440)

      PC's are not mainframes, 50 years? some guys in the 70's wanted a computer, half decade later it was already an industry ... I think your skewing this a little too hard

  • Depends on the flavor of cat.

    It is not so much of "will it" as opposed to "when will it." And to what degree of success & usefulness. I'll give the timeline roughly around the same time as fusion.

  • Two qubits should be enough for anyone.

    Oh c'mon, somebody had to say it. Might as well save some budding tech CEO from being cursed with that quote for all time.

  • Didn't all of these things take 30+ years to develop?
  • by Anonymous Coward

    Lockheed-Martin already bought one. It's made by D-Wave Systems and is called the D-Wave One. It is known as the first commercial quantum super computer. It has 128 qbits and has been out for about a year already.

  • It has to be able to run Doom. And Barney Doom.

    And, obviously, Linux. OpenBSD would be the Big Win.

  • by Toonol (1057698) on Monday September 26, 2011 @03:04PM (#37518772)
    While I'm highly skeptical about building a useful general-purpose quantum computer, I think that there may be great value in incorporating that tech into traditional computers. In other words, a four-qubit computer may be nearly useless except for very specific problems; but if it was part of your desktop computer, it would give it a large boost in all sorts of power.

    For instance, encryption is highly related to compression. I believe that a quantum computer would be highly efficient at compressing and decompressing data... which is a task CPUs (and GPUs) do a lot.
    • In other words, a four-qubit computer may be nearly useless except for very specific problems; but if it was part of your desktop computer, it would give it a large boost in all sorts of power.

      Not really; a four-qubit quantum computer can be simulated very fast in today's computers. It would be completely useless for any practical purpose (unless quantum computer fabrication technology improvements become ridiculously better than improvements on classical computer fabrication technology for an extended period of time).

      To simulate the evolution of an n-qubit quantum computer all you have to do is (essentially) multiply a vector of size 2^n by a series of 2^n-by-2^n matrices whose entries are compl

  • can it run crisis 2 at full speed with at least 60fps at full detail?

  • I imagine quantum computers will be possible, but only after a fundamental change in how we think about and design things. Sort of like how future technology was imagined in the 30's and 40's. It took the invention of the transistor and other solid state devices to get people to re-think how things could be designed.

  • The quantum summary quantumly mentions many quantum uses of the word quantum.

    And for some filler, maybe they'll make a quantum grill to quantum barbecue quantum burgers and quantum hot dogs.

  • We struggle to keep quantum computer IN lab!

  • You can't build a quantum computer here because we're a simulation already running in another quantum computer and there isn't enough resolution in the simulation's space time manifold to support the necessary function of another quantum computer. Duh!

    • Just like how I cannot run a copy of windows on my windows computer....

      Oh wait...

      VirtualBox

      Maybe we can run quantum computers but they will run very crappily and have the potential to crash the universe.....

  • All theoretical physicists should be hung by the chalk covered thumbs. Shouldn't we maybe......oh I don't know......INVENT SOMETHING!!!!!!!! What happened to all the scientists that actually experimented with real world problems and solutions that are within our grasp rather than take a hit of acid and calculate PI to a million digits. Especially seeing as how most of the field is based on the great moron's (einstein) postulate that NOTHING can travel faster than light. IT WAS A THEORY!!!!! STOP INVEN
    • The Oak Ridge Boys (not the band) invented a power source of the future for the whole world inthe late 60's / early 70's but the DOE had a vested interest in making bombs instead and since this new tech would eat bomb parts as fuel they were dismissed and ignored because they were so "heavily vested in current tech" which was ironically invented by the same guy who came up with the new tech.....

      Such is the ways of foolish government agencies and the companies that lobby them.

  • I, for one, am putting my bets on neutrino computing.

    Using neutrinos faster than the speed of light, it will be possible to send messages back in time, thereby enabling any kind of brute force algorithm. Just do a brute force search, and instantly receive a message from the future containing the answer to your problem.

    • This will break even passwords that only allow one try as you send a msg back in time that AAAAAAAAA didn't work , try somethign else. You will always get the correct answer back.

  • Because of the impact of Q.C. on crypto systems, I think it unlikely that the announcement will rapidly follow a real practical breakthrough development. Unless there is a very strong willed stinker on the development team, who can resist the bribes and threats, the policy is going to be to keep it under wraps as long as possible. The news will throw the financial community into a panic as no electronic encryption or signature systems will be considered reliable. There is too much money at risk for a prod

  • by drolli (522659) on Monday September 26, 2011 @07:51PM (#37521670) Journal

    Yes. it will. the time frame for QC leaving the lab is something from 15 years to 50years. If it doesn't work in the next 50years it means we understand something about quantum mechanics significantly wrong (or we figured QC is useless for some reason).

    There are several milestones:

    1) implementing single qubits (done in many systems) and high fidelity readout (done on a few systems)

    2) high fidelity operations on single qubits (done on some systems)

    3) controllable coupling of qubits (done on some systems) witn good on-off ratio (done on a few systems) in a decent architecture (only very few experiments AFAIU) with a demonstration of simple QIP algorithms (done)

    4) scalability in the production yield for solid state systems (NOT done, by far not) or in the resource usage for other systems (atom chips are promising)

    5) Quantum media conversion between solid state and optics (done) with decent fidelity (far, far away) for using QIP in Quantum communication as local processors

    6) Error correcting schemes to lower the threshold for 2) to a doable value for building a scalable computer (that is, a computer which gains computational power when ressources are added): theroretical (done) and experimental (far away)

    7) Theoretical understanding of QIP Architecture (not done)

    6, which implies 1-4 (and depending on the scheme also 5) have been solved is the criterion for building an arbitrary powerful QC for arbitrary money. The more you exceed the absolute thresholds imposed onto 2) and 4) the more power you will gain by adding resources (it could be 10 or 10000 physical qubits needed for 1 logical qubit). The question is: when will it be economical to build it? I cant answer this, but the first thing where it may pay off is for protein folding simulations. We are looking at replacing a 100MW input power classical computer by a some MW input power quantum computer (condensing helium). We may look at power cost savings of 10 to 100million of dollars per year runtime of the QC. Currently the schemes which are predicted to scale with current HW (on the rather optimistic end, i.e. the best experiments ever done) may require roughly a 100Million - 1billion Dollar investment into Hardware alone per QC (hand waving approximation), obviously unacceptable. However if the price goes down by a facto of 10 to 100 (which could happen in the next 20 years if better material or schemes are found), then it would be economical.

  • "Will Quantum Computing Make It Out of the Lab?" Is an interesting but isn't asking it result in changing the outcome?
  • ...steampunk a quantum pyewta?
  • I don't believe it will. Quantum bits just don't scale as well as normal bits, because they must be entangled. That's the problem.

    If I have a working n (normal) bits, it's quite easy to make 2*n bits (just produce the same thing twice and add some circuitry). But with quantum bits, if you have n qubits working, even n+1 qubits is an engineering challenge and 2*n qubits is a major research effort.

    And because it scales so badly, it won't become practical. So, your quantum computer broke the crypto on 300 bits

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