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Tiny Holes Advance Quantum Computing

Posted by CmdrTaco on from the nothing-is-something dept.

Nick writes "Worldwide, scientists are racing to develop computers that exploit the quantum mechanical properties of atoms - quantum computers. One strategy for making them involves packaging individual atoms on a chip so that laser beams can read quantum data. Scientists at Ohio State University have taken a step toward the development of quantum computers by making tiny holes that contain nothing at all. The holes - dark spots in an egg carton-shaped surface of laser light - could one day cradle atoms for quantum computing."

11 of 255 comments (clear)

  1. Great principle by treff89 · · Score: 5, Funny

    Quantum computing is quite simply where we turn after existing silicon is exhausted. Once the basics about the random nature of quantum particles, which is extremely interesting, the meaning of computer and mechanics thereof can be redefined.

    1. Re:Great principle by Urkki · · Score: 5, Informative
      • they're not an improvement over silicon for everything.

      Indeed, talking about quantum computers as an improvment on silicon computers is like talking about jumbo jets as an improvement over cars. Ie not an improvment at all, unless you have something very specific to do (factor a large integer or cross an ocean). And you need the simpler alternative to use the more advanced one (car to get to the airport, regular computer to feed and extract data for quantum computing).
    2. Re:Great principle by AKAImBatman · · Score: 5, Informative

      Quantum Leap was an excellent TV show that ran through the late 80's and early 90's. The premise was that "Dr. Sam Becket" (who now plays Captain Archer on Enterprise) invented a time machine that would allow him to reach points throughout his lifetime. The problem is that he never quite got the kinks worked out of his retrieval program, and now finds himself randomly leaping from life to life. The tagline of the show was, "striving to put right what once went wrong and hoping each time that his next leap will be the leap home." (Usually then followed by us seeing him leaping into someone's life. Something utterly confusing then happens to him and he utters the words, "Oh boy".)

      And now you know... the rest of the story.

      --
      Javascript + Nintendo DSi = DSiCade
    3. Re:Great principle by stevok · · Score: 5, Interesting

      Not exactly. Quantum computers can simulate classical computers with no problems. That's one of the tenets of quantum computation. I would love to see a 747 parallel park in Manhattan. Also, the fact that quantum computers can factor large integers efficiently necessarily implies that they can do other NP-complete problems efficiently, such as the traveling salesman problem. If we can ever get more than seven qubits to behave, we'll be amazed by the things quantum computers can do. But, alas, scientists have only implemented Shor's Algorithm for factoring integers on one number. 15. And hot damn, they got the factors right, 3 and 5. Yes, IAWAUGTOQC (I am writing an undergrad thesis on quantum computation).

    4. Re:Great principle by QuantumFTL · · Score: 5, Informative

      Not exactly. Quantum computers can simulate classical computers with no problems. That's one of the tenets of quantum computation.

      If by "no problems" you mean "severe and most likely insurmountable quantum coherence issues". Any quantum computer big enough to simulate a modern sized classical computer will contain so many qubits as to have problems with interference from the outside world. IIRC the problem of quantum coherence is roughly exponential in the number of qubits in a system (one of the reason we don't have 1000 qubit computers sitting around). Just having enough qubits to remember my RAM would get pretty ridiculous.

      The truth is that quantum computers, in the forseeable future, will likely be an orthogonal type of computing system to classical computers - a coprocessor used for certain problems with small memory requirements but large search spaces. Many of our most important computations lie in this regime, but I doubt quantum computers will outperform classical computers on most ordinary stuff (i.e. word processing, running a webserver, handling large databases) due to its seriality and memory intensive nature. (Insert quote like "640 k ought to be enough for anybody" here)

      Also, the fact that quantum computers can factor large integers efficiently necessarily implies that they can do other NP-complete problems efficiently, such as the traveling salesman problem.

      It implies no such thing. Traveling salesman problem is NP-complete, and while we have no solid proof that a quantum computer cannot solve an NP-complete problem in polynomial time, Shor's algorithm is also in no way any kind of proof, as integer factorization is merely NP, not fully NP-complete as you claimed.

      Yes, IAWAUGTOQC (I am writing an undergrad thesis on quantum computation).

      Yes, I do have a degree in physics. You may wish to check said thesis in light of errors explained above.

  2. Definitions? by Rinzai · · Score: 5, Funny
    "...making tiny holes that contain nothing at all."

    Well, yes, that rather is the definition of "hole," isn't it? Having nothing in them is what distinguishes them from the rest of the surroundings.

  3. Mind Boggling by CleverNickedName · · Score: 5, Funny

    Scientists ... making tiny holes that contain nothing at all.

    So these boffins have developed "nothing", but one day, in the far future, this nothing could be filled with something important.
    Wow. What an age we live in.

    --


    Unfortunately, I am not Wil Wheaton
  4. obligatory Simpsons quote: by TheAxeMaster · · Score: 5, Funny


    They're speed holes, they make the computer go faster....

  5. Re:If Schroedinger is anything to go by. . . by x4A6D74 · · Score: 5, Insightful
    The computer does not ask "is it one or zero" and get told "both."

    Going back to the same metaphor you began to use, the principle that the Schroedinger's Cat Experiment is suppposed to illustrate is not the concept of superposition (that the cat is both alive and dead whilst in its quantum state in the box) but the concept of decoherence of the quantum state under observation.

    It's currently a postulate of quantum mechanics (i.e. everyone observes this phenomenon but nobody can explain it) that observation of a quantum state in a superposition (say, a "qubit" -- perhaps an electron spinning up for 0 and down for 1) will have one of the two values, with certain probability. Once read, the state loses that superposition and remains in the observed state (Recall: in the SCE, the cat stays alive or dead once you open the box).

    If you don't want to measure your qubits, and thus maintain their superpositions, entanglements, etc., that's fine ... of course, you can't get any information out of them. If you've properly designed your quantum machine, you may have a guess as to what the possible states are; you may even know the probability of each one.

    As soon as you ask to see a qubit, however, it becomes a classical bit and stays one. That's the downside to all this quantum stuff.

    Quantum computers also do not mean an end to binary -- currently, since humans have, and are trained to use, primarily classical faculties, quantum research is aimed at extending classical computation. So we typically discuss a "qubit" which may be 0, 1, or some combination thereof (specifically residing in the field C x C). But, if we ever want to interface a quantum computer with a classical instrument (for example, some sort of I/O device, or a classical computer, or a human) then we will unavoidably devolve back to binary.

    For more information, I recommend Nielsen & Chuang's book on Quantum Computation and Quantum Information (I think; I don't have it in front of me right now).

    Disclaimer: I am not a quantum mechanic. I am, however, an junior finishing up my degrees in mathematics and computer science so that I can go on in a year to work on a PhD in quantum computation. --0x4a6d74

  6. Factoring is NOT known to be NP-complete by Catullus · · Score: 5, Informative

    In fact, it would be very surprising if it turns out to be NP-complete, as it is in NP intersect co-NP. Also, no efficient quantum algorithms are known for NP-complete problems, and it is generally suspected that quantum computers won't be able to solve them efficiently. For example, see this semi-technical paper.

    You had better get that right in your undergrad thesis ;)

  7. Re:Wow by madaxe42 · · Score: 5, Interesting

    You can actually guarantee that it will be empty, by creating wave functions that overlap in such a fashion that the probability of a particle being in that space is, in fact, 0, or, by creating wavefunctions which when combined state that the probability of there not being something in that location is infinite. Picture two asymptotic curves joining at a vertical axis, mirrored.

    There are a lot of extremely odd quantum effects which aren't physically possible, in any classical or comprehensible universe, however do happen. For instance, it's possible to create a negative temperature. Not negative, as in minus 22 farenheit, but negative, as in below absolute zero!

    This happens when you rapidly invert the polarity of a magnetic field in which is contained a bose-einstein condensate - in the time that it takes for the condensate to re-align it's spin, it has a rapid change from a negative temperature to a positive temperature once more. The energy of a negative temperature is, actually, greater than that of an infinite positive temperature!

    Anyway, enough quantum rambling. If you don't believe me, look here.