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Experts Hail Quantum Computer Memory Stability Breakthrough

Posted by Soulskill on from the long-enough-to-play-some-quake-3 dept.

cold fjord writes "The BBC reports, 'A fragile quantum memory state has been held stable at room temperature for a "world record" 39 minutes — overcoming a key barrier to ultrafast computers. 'Qubits' of information encoded in a silicon system persisted for almost 100 times longer than ever before. ... "This opens the possibility of truly long-term storage of quantum information at room temperature," said Prof Thewalt ... unofficially, the previous best for a solid state system was 25 seconds at room temperature, or three minutes under cryogenic conditions. ... What's more, they found they could manipulate the qubits as the temperature of the system rose and fell back towards absolute zero. At cryogenic temperatures, their quantum memory system remained coherent for three hours. "Having such robust, as well as long-lived, qubits could prove very helpful for anyone trying to build a quantum computer," said co-author Stephanie Simmons of Oxford University's department of materials. ... "We've managed to identify a system that seems to have basically no noise." However she cautions there are still many hurdles to overcome before large-scale quantum computations can be performed. ... "This result represents an important step towards realizing quantum devices," said David Awschalom, professor in Spintronics and Quantum Information, at the University of Chicago. "However, a number of intriguing challenges still remain." — Abstract for the paywalled academic paper."

53 comments

  1. They will break all the encryption by Anonymous Coward · · Score: 0, Interesting

    The second they perfect this, they will be able to try all the keys at once and the right one will be solved instantly. All of our current generation of encryption relies on n-p complete algorithms and will become worthless ... the banking system and world economy will follow suit. Time to buy that potato farm in Idaho...

    1. Re:They will break all the encryption by harvestsun · · Score: 4, Informative

      That's probably the most common misconception about quantum computers... They do not solve all NP problems efficiently, only a subset called BQP: "bounded error, quantum, polynomial time". It is believed that this is completely disjoint from the "NP complete" subset.

    2. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      Yes, and I expect quantum computing to be never released to the general pubic.

    3. Re:They will break all the encryption by JoshuaZ · · Score: 5, Informative

      The second they perfect this, they will be able to try all the keys at once and the right one will be solved instantly. All of our current generation of encryption relies on n-p complete algorithms and will become worthless

      There is a lot wrong with this.

      First of all, quantum computers cannot as far as we know solve NP-complete problems efficiently. There's no known way for that to happen, and most experts expect they cannot. What they can do, is solve specific classes of problems more efficiently than classical computers. The most obvious example of this is factoring integers, which seems to be very difficult for a classical machine, but which can be done quickly by a quantum computer using Shor's algorithm. http://en.wikipedia.org/wiki/Shor's_algorithm

      Second, none of these algorithms are instantaneous or even remotely so, but rather scale wit the size of the input, generally with a polynomial.

      Third, while many forms of crypto would be vulnerable, including RSA and elliptic curve cryptography, not all forms of cryptography have known vulnerabilities. This connects with the earlier issue of NP completeness. No form of crypto relies at this point on an NP complete problem. Factoring for example is in NP (which means roughly that one can easily convince someone that one actually has the factorization), but it is likely not NP complete. A problem is NP complete if (roughly speaking) it lives in NP, and if you have access to a black box that solves the problem then you can solve all NP problems. At this point, factoring is strongly suspected not to be NP complete, because that would lead to the collapse of the polynomial hierarchy http://en.wikipedia.org/wiki/Polynomial_hierarchy, which is strongly conjectured to occur.

      Quantum computers will likely have real world consequences if we ever get them to work on a large scale, and some of those consequences will be cryptographic. But thinking that they'll somehow blow up all cryptography is just hype. If you want to read a good book, without hype, that does a good job of explaining how quantum computing actually works, I recommend "Quantum Computing Since Democritus" by Scott Aaaronson. The book does assume some slight comfort with linear algebra, a very tiny amount of group theory, and some calculus, but that's it. It is aimed at people in technical fields other than quantum computing to understand what it is about. It is highly readable, and I strongly recommend it.

    4. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      Time to investigate quantum encryption.

    5. Re:They will break all the encryption by Anonymous Coward · · Score: 1

      Time to buy that potato farm in Idaho...

      PROTIP: Use your Bitcoin to buy the farm.

    6. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      More likely, there would suddenly be a huge demand for unbreakable quantum encryption, followed by massive investment in developing quantum computing technologies.

    7. Re:They will break all the encryption by fuzzyfuzzyfungus · · Score: 2

      More likely, there would suddenly be a huge demand for unbreakable quantum encryption, followed by massive investment in developing quantum computing technologies.

      Unless they mean something rather different by 'quantum encryption' than the present usage, it won't be of much use.

      If you are particularly paranoid, and operate on the theory that your fiber isn't being tapped, quantum encryption comes in at a price that compares favorably to having trusted guys with guns stand around keeping people away from your fiber. If, however, you don't have the luxury of a continuous run between you and the destination (like, oh, almost everybody), the fact that a third party has access to your photons isn't news, it's how the network networks.

    8. Re:They will break all the encryption by JoshuaZ · · Score: 4, Interesting

      Er, "strongly conjectured to occur" should be "strongly conjectured to *not occur*. Need to proofread more when using preview. Also, as long as I'm replying to myself, note that the set of problems which can be solved easily by a quantum computer is BQP http://en.wikipedia.org/wiki/BQP, but it is likely that for many practical applications, one will want the set of problems where a quantum computer can quickly convince a classical computer that it really has a solution, and this set, ZBQP, is likely much much smaller https://complexityzoo.uwaterloo.ca/Complexity_Zoo:Z#zbqp. Factoring lives in this smaller set because the classical computer can check the quantum computer's work essentially by just multiplying together the factors given by the quantum machine.

    9. Re:They will break all the encryption by sd4f · · Score: 4, Interesting

      I actually went to a talk by a Prof. Michelle Simmons on this last night, and asked that question. My understanding is that it would just does all the calculations at once, in a massively parallel operation (which obviously isn't efficient). I'm no computer scientist (just a mechanical and mechatronic engineer) and I don't really know anything behind quantum mechanics, but the other thing mentioned in the talk about a quantum computer is that it would have perfect security (her words), because, and now i'm relying on memory, a quantum computer doesn't store data like a classic computer, as it can't be perfectly replicated, so the quantum computer needs to keep the qubits active for as long as possible in the computer (hence the importance of the coherence time, as stated in the article). Because a quantum computer is an adiabatic system, it sends the 'energy' from one place to another. Eavesdropping would mean you reroute that energy, and it doesn't go to its intended place.

      A lot of it went over my head, so take this with a spoon of salt, as I could have botched it up, but that's the gist of my understanding, and off-topic info

    10. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      As far as I'm currently aware, Quantum Computers will do close to nothing.

      The one thing I know they can do is breaking *asymmetric* encryption quite quickly (but only asymmetric).

      One thing they are not going to do for sure is providing us with general-purpose "ultrafast computers", to cite the article. Programming a quantum computer is hard, and the problems they are currently known to be efficient in solving are very, very specific. I consider it highly improbable that quantum processors will ever replace "classical" CPUs; at best you might get something like a quantum coprocessor at some point, like you have a floating point coprocessor now.

    11. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      I don't think you quite understand how quantum encryption (or rather, quantum key exchange) works. What you send over the quantum channel is simply a key for a traditional shared-key cryptosystem (which generally have not been shown to have any weaknesses specific to quantum computing, and thus would not seem to be any less secure in the event that quantum computers are made real than they are currently). The advantage of the quantum channel here is that a man in the middle cannot eavesdrop without being detected. Thus the only thing an eavesdropper could get is a shared key that will never be used (because the parties trying to communicate know that the key has been compromised). Of course, a man in the middle could still effectively shut down the quantum channel by eavesdropping on everything -- but then, a man in the middle could just take a pair of scissors to the cable as well.

    12. Re:They will break all the encryption by fuzzyfuzzyfungus · · Score: 1

      That was my intended point: very few entities actually have a quantum channel between point A and point B. Virtually everybody, even the ones with fiber links, has a link to some local telco or peering point and then is N hops away from their destination. At present (and barring substantial advances in all-photonic switching), that means that a 'compromised' quantum channel is the expected state, since there are multiple hops between you and your destination.

      If you have the cash for old-school point-to-point hard lines between your facilities, quantum encryption offers a (relatively) cheap way of checking link integrity; but that helps relatively few people. If traceroute says you are more than one hop away from your destination, you probably aren't one of them (again, barring substantial advances in switching technology that allow preserving the quantum properties of photons).

      To the best of my (layman's) knowledge, the stuff is ironclad within its area of ability (unlike classical crypto schemes, which tend to make people a bit nervous); but its area of ability is actually really small. It's more of a link-integrity verification system(and one that, since it depends on subtle physical properties, only works over physically continuous links, no VPN-type cases) than a drop-in for classical encryption.

    13. Re:They will break all the encryption by JoshuaZ · · Score: 1

      So, the result for encryption may not be that large, but that's by far not the only thing that people want to use quantum computers for. They can be used to optimize a number of problems that show up in real world conditions, and do quantum simulations for chemistry where actually observing the reactions in detail would be too difficult.

    14. Re:They will break all the encryption by TheTrueScotsman · · Score: 1

      Symmetric (shared-key) algorithms do have vulnerabilities to quantum computing: Grover's algorithm allows a brute-force search to be performed in square-root time of the key size (i.e. 256-bits -> 128-bits, 128-bits -> 64-bits). This isn't a big problem as long as you're using at least 256-bits.

    15. Re:They will break all the encryption by HuguesT · · Score: 1

      Unless P=NP of course, in which case they are all in the same class.

    16. Re:They will break all the encryption by HuguesT · · Score: 1

      Yes, quantum computer ought to be really efficient at simulating quantum phenomena. This is really useful, because simulating them on classical computers is very inefficient, and so our understanding of many physical processes should improve.

    17. Re:They will break all the encryption by JoshuaZ · · Score: 1

      Actually, this does not follow either. Right now it is open if BQP (the set of decision problems solveable by a quantum computer in polynomial time http://en.wikipedia.org/wiki/BQP) lives in the polynomial hierarchy http://en.wikipedia.org/wiki/PH_(complexity). Most complexity classes we care about live between P and NP, but it turns out that PH (a class believed to be much larger than even NP) will also collapse to P if P=NP, so there are larger complexity classes that also collapse if P=NP. However, it is open as to whether BQP lives in PH. So it is consistent with what we know now for it to be true that P=NP but BQP != P. That would be a weird situation, but possible.

    18. Re:They will break all the encryption by Anonymous Coward · · Score: 0

      Quantum computers, assuming enough qubits to match key lengths, can break current factor based public key encryption in the same number of operations it takes to encrypt the data in the first place. Quantum operations take longer than classical, but in the end, it's an O(1) operation.

  2. Nice, but... by Anonymous Coward · · Score: 0

    I'm sure there's hundreds of three letter agencies around the world waiting to get their hands on these.

    Message integrity checking is a nice counter feature, though.

    1. Re:Nice, but... by Ashenkase · · Score: 4, Funny

      I fail to see how KFC can leverage this technology... unless of course... they can make the elusive "n" down sandmich. O now that is ebil.

    2. Re:Nice, but... by Joining+Yet+Again · · Score: 2

      I would assume that the NSA is at least a decade ahead of open academia on all problems relevant to them.

    3. Re:Nice, but... by cold+fjord · · Score: 4, Interesting

      I would guess 15-20, more or less, depending on the specific application. The history of the NSA's involvement with the DES encryption algorithm is instructive.

      NSA's involvement in the design (of DES)

      I would also highlight the last sentence in the section: " Bruce Schneier observed that "It took the academic community two decades to figure out that the NSA 'tweaks' actually improved the security of DES."[12] "

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
    4. Re:Nice, but... by mmell · · Score: 1

      AAA and the NRA, OTOH...

    5. Re:Nice, but... by Anonymous Coward · · Score: 1

      I am not sure about such assessments. It's known that the NSA and GCHQ hit on public key cryptography just a few years before academia did, in the 70s. However, at the time cryptography research in academia was not all that widespread, at least not in the west, probably in part because of pressure from said agencies. Analogously with DES. Likewise, there are strong indications that the development of ECC caught the NSA by surprise. These agencies no doubt have a far deeper hands-on experience that researchers in academia, but it is highly unlikely that they are more than a few short years ahead, if at all, in the theoretical department.

    6. Re:Nice, but... by cold+fjord · · Score: 2

      I think another chain beat them to it. Isn't there an Arby-Qbit sandwich?

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
    7. Re:Nice, but... by cold+fjord · · Score: 2

      Hard to say. Anyone can come up with a new idea, but only the spooks get to see everything they have plus what academia produces. As the biggest employer of mathematicians they have the potential to take a new idea and explore or develop it quickly. But it is also the case that math breakthroughs can hinge on the breakthrough insights of a single gifted (or gifted and dogged) individual. It is also the case that the details of a particular technology matter. If you compare the gross scheme of the Enigma to the US SIGABA systems, they are in many ways comparable. But the SIGABA was a much more secure system than Enigma. The Germans never made a dent in it, and it was good enough to be used for years after WW2.

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
    8. Re:Nice, but... by mikael · · Score: 2

      A couple of decades ago, even discussions on the factorisation of integers would be discouraged by the FBI, and exports of software that did 128-bit encryption and above required an official federal application for an export license.

      --
      Vintage computer adverts: http://www.vintageadbrowser.com/computers-and-software-ads
    9. Re:Nice, but... by Anonymous Coward · · Score: 0

      I was in the Dutch beta program for Windows 2000. At some point I received a CD with an update which did nothing more than unlock 128-bit encryption for me. That's not "a couple of decades" ago, that's only 13 years ago.

    10. Re:Nice, but... by Anonymous Coward · · Score: 0

      I would guess 15-20, more or less, depending on the specific application. The history of the NSA's involvement with the DES encryption algorithm is instructive.

      This is a question of some import to the field of computer security. Since there are experts in the field, I would tend to follow Bruce Scheier's opinion. It took the community of cryptanalysts outside of the NSA 20 years to figure out differential cryptanalysis and why the NSA's tweaks to DES were a Good Thing(tm). In 1999 the community figured out a weakness in SHA-0, merely 4 years after the NSA. In 2004 a weakness in SHA-1 was published which it is believed the NSA did not know about. So, years ago the NSA was far ahead of everyone else, but now the NSA might be a year or two ahead on average.

    11. Re:Nice, but... by cold+fjord · · Score: 1

      I think you made a great post. As Bruce notes in that piece, nobody knows. You also can't overlook the possibility that they hold back on vulnerabilities until an exploit for them is in reach of the public or some other adversary. It is also worth noting that working on this year's NIST standard isn't all they do. There are about 200 countries out there, and plenty of different encryption schemes to keep them busy cracking. They also have their own US government codes design, test, and vet. There is also the fact that having a head start only gets you to the mountain quicker, climbing it is still slow work. And as I noted in my other post, anyone can have a brilliant idea.

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
  3. /., news you saw yesterday by Anonymous Coward · · Score: 0

    Any chance of getting a non-advert news item when every other feed has it, not the day after the mainstream media has already covered it?

  4. And it was so simple to do... by TempeNerd · · Score: 4, Interesting

    I am just amazed at the technology that is going into making this new qubit.

    First off it is "...built with a highly purified form of silicon" and one qubit requires "... the spins of the 10 billion or so phosphorus ions..."

    Now THAT is engineering!

    1. Re:And it was so simple to do... by TheSync · · Score: 1

      The problem is that I don't think anyone has ever built a quantum gate with phosphorus doped silicon...

  5. Noise by Anonymous Coward · · Score: 0

    Now they need to figure out why this composition has less noise. That will be the real breakthrough.

  6. Just a few observations . . . by mmell · · Score: 1
    First - while quantum computing may well make certain forms of encryption less trustworthy, it will also introduce new forms of encryption which are at least as trustworthy as the preceding.

    Second - quantum computing is only just now barely becoming a tantalizing possibility under laboratory conditions which are unlikely to ever translate well to consumer/commodity hardware or mass production. In fact, it seems likely to remain the domain of "three-letter agencies" (and universities and large enterprises and the independantly wealthy) for some time to come. Unfortunately, this renders my first point somewhat academic, as most consumers will have to either use vulnerable forms of encryption or find forms which quantum computing does not significantly weaken.

    Third - never mind, I only had two.

  7. Windows by TVDinner · · Score: 5, Funny

    39 minutes.....that's long enough to run Windows between BSODs

    1. Re:Windows by Anonymous Coward · · Score: 0

      Haha! Classic.

    2. Re:Windows by Anonymous Coward · · Score: 0

      Yeah, "classic" in the sense that the joke is old. These days my ancient Windows XP partition is rock solid while every other Linux kernel update fails to boot and when it does work X crashes every half hour or less due to a buggy driver for the stock Intel onboard video. I've changed distros and hardware; on the last computer it was a buggy nvidia driver locking up the entire system from time to time. So this is one of those "Linux is not ready for the desktop" posts that I never thought I'd write. When it can't run on some of the most common mass-market hardware out there, it's not ready.

    3. Re:Windows by Anonymous Coward · · Score: 0

      Typing this from my perfectly fine common mass-market desktop running Linux... just like the one before it, and the one before that right back to around 1998 I think. No instability, no crashes, none of the sort of problems you describe. Windows? I won't touch hat steaming schizophrenic heap of misery unless someone pays me quite handsomely to do so.

  8. Another observation by Okian+Warrior · · Score: 4, Interesting

    We are also testing the boundaries of the physical universe in a completely new realm.

    The number of states in a quantum-entangled set of particles goes exponentially with the number of particles. For 10 particles (entangled) it takes 2^10 states for the universe to represent the possible outcomes. For 1,000 entangled particles, the number of states is 2^1000.

    The number of particles in the entire universe is only about 2^80.

    Managing 1,000 entangled particles would require the universe to keep track of a staggering amount of information. Does the underlying machinery have information-space this big? No one knows.

    For the first time, we can measure the boundaries of the physical mechanism that underlies the universe in a completely different realm: information capacity. This is analogous to a program probing the limits of RAM memory by seeing how much it can allocate.

    Here's hoping that we don't find a buffer overflow.

    1. Re:Another observation by cold+fjord · · Score: 1

      Managing 1,000 entangled particles would require the universe to keep track of a staggering amount of information. Does the underlying machinery have information-space this big? No one knows.

      Quantum entanglement appears to be a key element of photosynthesis, and systems of more than a hundred million entangled photons have been achieved.

      --
      much of left-wing thought is a kind of playing with fire by people who don't even know that fire is hot - George Orwell
  9. Wrong number of atoms in the Universe by Myria · · Score: 2

    It's about 10^80, not 2^80.

    I think we'll find that the amount of energy required to hold X entangled particles in coherence will be exponential in X. This would make quantum computing essentially worthless.

    If not, wake me when we get to 2048 qubits, for the original Xbox's public key and I have some unfinished business from last decade...

    --
    "Screw Sun, cross-platform will never work. Let's move on and steal the Java language." - Visual J++ Product Manager
  10. Good catch by Okian+Warrior · · Score: 1

    It's about 10^80, not 2^80.

    Good catch. I misremembered the number from my original source, which also lists it as 10^80.

  11. What a load of crap by TomGreenhaw · · Score: 1, Funny

    Quantum entanglement - really??? Can a cat be alive and dead at the same time? Huh???
    Could all this be non-science and a misinterpretation of statistical math that doesn't really describe reality?
    The underpinning of quantum computing is the idea that a qubit has the ability to be in more than one state simultaneously. This is simply illogical.
    Don't shrug it off and say "things work counter-intuitively at the subatomic level"; that's a philosophical cop out and is not science.
    The quantum is a profound realization that electrons can only be at discreet energy states based on the wave like nature of electrons whose energy state can only exist in even multiples of their wavelength. Why is the term being commandeered to imply that quantum can represent multiple states simultaneously.
    The theory is that a single qubit can represent a one, a zero, or any quantum superposition of these two qubit states. Quantum superposition is a useful statistical tool and that is all. To go out on a limb and try to actually engineer useful machines on this concept - well good luck with that.
    True quantum computing where single atomic energy states, spin and other subatomic energy states are used to represent information can keep Moore's law alive for decades. Hopefully not too much time and energy will be wasted on magic, smoke and mirrors and pseudo-science.

    --
    Greed is the root of all evil.
    1. Re:What a load of crap by JoshuaZ · · Score: 1
      Your point that the word "quantum" originally referred to the discretized nature of energy states is true but unhelpful. Words have distinct meanings apart from their etymology. Don't think that because scientists started using a word because of it having one Greek root doesn't mean they cannot use the word in a more general context when they are clear about what they mean.

      The underpinning of quantum computing is the idea that a qubit has the ability to be in more than one state simultaneously. This is simply illogical. Don't shrug it off and say "things work counter-intuitively at the subatomic level"; that's a philosophical cop out and is not science.

      Actually, if anything, this is a biological/psychological statement. You are confusing logic with intuition. Humans evolved on the medium scale, where things aren't very large or very small, not very hot and not very cold, etc. So we have good physical intuition there. You shouldn't expect your intuition to be more than a rough guide outside that range. When math and empirical experiments contradict intuition, the thing that needs to be adjusted is almost invariably intuition, not math.

      Quantum superposition is a useful statistical tool and that is all

      So, whether or not some deep weird thing is happening, if you agree that these statistics do describe accurately what results to get, then you should expect a quantum computer work. But it may be worth noting that this is a common response to things people don't like. When the Copernican system arose, people tried to argue that it should be seen as only a calculational tool, rather than an actual description of the solar system, and that got extended even to Kepler's system. Similarly, in the 19th century, people suggested that one should view atoms as a convenient fiction. In general, arguing that some state of nature implied by a model is fictitious even while you think that the model gives near perfect descriptions has a bad track record. The only times this turns out to be the case is when it turns out something is genuinely wrong with the model itself, such as the plum-pudding model of the atom. But in fact this is part of why physicists are interested in quantum computers- they provide a novel way of testing how quantum mechanics functions. If in fact it turns out that they don't do what we expect them to do, then that will mean basic aspects of physics as we understand them are wrong, and so we'll learn from that.

    2. Re:What a load of crap by TomGreenhaw · · Score: 1

      "if you agree that these statistics do describe accurately what results to get"
      Yep, I agree completely and that's why I say that statistical formulas can be useful for large numbers of entities. But for a single particle - nope - not the right tool. And herein lies the core the argument - Bohr vs. Einstein
      My position is that Einstein was right, God does not play dice and the universe is fully deterministic. Unfortunately the mathematical model to describe a deterministic universe would need to take into consideration the state of every single charged and massive particle in the universe - obviously not possible - but that's our reality. Statistical math comes to the rescue and provides an acceptable and useful model that will match experimental evidence for bulk entities. This is much like a road map which is a very useful tool, but we must remember that the width of the lines representing roads are not to scale.

      " it may be worth noting that this is a common response to things people don't like"
      I love the idea of a quantum computer. I seriously hope the position I've taken is wrong, Quantum computers that take advantage of entanglement and superposition would be some seriously awesome magic whose ramifications are unimaginably profound. It would arguably be the important advancement humanity has ever produced to date. Unfortunately I don't think a breakthrough can be around any corner. Its a high stakes gamble for researchers to pursue, and it must be pursued. But we cannot depend on success any more than buying a lottery ticket to feed a family.
      If theoretical advancements in physics turn out to be a trip down a blind alley based on false assumptions, its important for people to consider alternative ideas. Because my career isn't in theoretical physics, I can get away with making controversial statements that at least should be considered.

      --
      Greed is the root of all evil.
    3. Re:What a load of crap by JoshuaZ · · Score: 1
      But we have gotten quantum mechanics to work well on single particles. There have been many experiments involving individual electrons or individual photons (fewer with photons since it is very difficult to send out a single photon). Moreover, this actually misses what quantum computers rely on: they aren't relying on the behavior of the individual particle as much as on the entangled state, exactly where you seem to think that the statistics works well. You may also want to look into Boson Sampling http://www.scottaaronson.com/papers/optics.pdf a very neat process which lets us verify in a very controlled setting that quantum systems can be used to compute classically difficult stuff. For small numbers of photons, Boson Sampling has been verified to do exactly this in experimental contexts: http://www.nature.com/nphoton/journal/v7/n7/full/nphoton.2013.102.html

      But we cannot depend on success any more than buying a lottery ticket to feed a family.

      No one is saying that we should "depend" on it. And there are serious physicists and mathematicians who do doubt that these systems will ever work, but most of that concern is practical: that the fundamental difficulties involved are just too big to ever scale to practical sizes.

      Because my career isn't in theoretical physics, I can get away with making controversial statements that at least should be considered.

      That you can "get away" with something isn't a reason to do it. And if your career isn't in theoretical physics, computer science, math, or particle physics, then that's all the more reason you shouldn't throw out controversial statements as gospel when they likely are wrong. There's a massive difference between "We should consider if maybe X is true" and "X is true."

    4. Re:What a load of crap by TomGreenhaw · · Score: 1

      You make two good points.
      "That you can "get away" with something isn't a reason to do it." I made a poor choice of words. The experiment described in TFA is actually very cool (pun intended). What I'm trying to say is that the people who have a lot at stake in this field are afraid to rock the boat by expressing their misgivings about some of the underpinnings of quantum computing. I'm not trying to win a nobel prize here or yell fire in a theater, my aim is to gain a better understanding of reality and strengthen physics in general. I don't see how a defense of the status quo against these kinds of arguments can do harm and in fact they strengthen science.

      "But we have gotten quantum mechanics to work well on single particles." I'll be sure to study what you have referred to. Previous review of experiments I've seen left me with the impression that the experimenters were failing to take into account the effects of the outside world on single particles and ignoring alternate explanations of the results. Its all to common to cloak to see these ideas in a thick armor of complexity and jargon but its worthwhile to review time permitting.

      --
      Greed is the root of all evil.
    5. Re:What a load of crap by JoshuaZ · · Score: 1

      On the contrary, if you talk to the people who are doing this, many of them acknowledge that something might not work, and they are eager for that because it would be a glimpse of new physics. At this point, we know that the Standard Model isn't all there is, but we don't know exactly where it breaks down. If we can set up what should be fully functioning quantum computers and then they don't do what we want, that will be Nobel Prize level discoveries by itself. As to your last bit, I don't know what you mean by "failing to take into account the effects of the outside world"- if anything quantum mechanical demonstrations generally require very careful consideration of external effects, because superposition breaks down very easily when contact with outside objects occurs. As to the claim that there's any sort of "cloak" or "thick armor of complexity"-most of the math involved doesn't require anything beyond linear algebra, but it is worth considering that somethings in life have complicated math because they are genuinely complicated.

    6. Re:What a load of crap by Anonymous Coward · · Score: 0

      That is the rub. You make it seem like scientists are too PC in terms of scientific...when it comes to new break-throughs. I would argue that this would hinder us in making those groundbreaking arguments in order to drive a new realm of science (or a new branch of physics).

      Note: I am not a physics major nor have taken physics at university. But the question I would have is: if quantum computing works and we *can* have a qbit in multiple states at the same time, wouldn't it stand that this is a slight indication or hint that a multi-verse would exist or perhaps teleportation? We already have seen from other experiments that quantum teleportation exists (at the atomic level). How could this be grown to a larger scale?

      Would fusion energy suffice for the power needs of such devices? Or would we need to find a way to actually harness or synthesis a super heavy element in order to create an artificial energy source? (if such a thing is even possible in physics)

      I think many people are held back of thinking radical ideas for fear of sounding like a crack-pot. But you know...not everything in this universe is known to us. When we find a break-through in such an area will we even know what we're looking at? Much of this science is well beyond our knowledge and into unknown territory. Even for physicists when they step out onto that unknown area they might know of 1 thing to check, but what about the other 50 things right in front of them that they don't see or know to look for?

  12. Experts Hail Quantum Computer Memory Stability Bre by Anonymous Coward · · Score: 0

    I wish they'd just deliver the goods or STFU. I'm so sick and tired of hearing about this or that invention or 'breakthrough' that doesn't translate to something I can use NOW.