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First Quantum Byte Created 261

Posted by CowboyNeal
from the future-arrives dept.
gila_monster writes "Juice Enews Daily is reporting that the Institute of Quantum Optics and Quantum Information at the University of Innsbruck in Austria has created an entanglement of eight quantum particles, yielding a quantum byte or 'qubyte,' or eight qubits. The formal paper was published in the December 1 issue of Nature. A qubyte with eight ions provides a computing matrix of 65536 mostly independent elements. No word in the article about whether they were able to actually use the qubyte for computing."
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First Quantum Byte Created

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  • by Anonymous Coward on Friday December 02, 2005 @06:05AM (#14164667)
    No word in the article about whether they were able to actually use the qubyte for computing

    I think we can be sure that if somebody had unlocked the secret of quantum computing there's a chance they'd say so at some point.
    • by David Hume (200499) on Friday December 02, 2005 @06:40AM (#14164758) Homepage
      I think we can be sure that if somebody had unlocked the secret of quantum computing there's a chance they'd say so at some point.
      Unless that someone worked for the National Security Agency [nsa.gov].
    • by Mjec (666932)

      I think we can be sure that if somebody had unlocked the secret of quantum computing there's a chance they'd say so at some point.

      Ummm... not quite. There's lots of quantum computing currently being done - 4 qbit computers exist in several places (or can be brought into existance on demand, anyway). Quantum computation requires entanglement and manipulation of entangled bits. Well, the former is the hard part - that's what's been managed here. A major step forward - I recall 6 qbits was the record ab

    • Even if this research carried out by the University of Innsbruck doesn't have immdeiate application it still another step on the difficult road towards Quantum Computing.
  • by LiquidCoooled (634315) on Friday December 02, 2005 @06:06AM (#14164672) Homepage Journal
    Wasn't there some news recently that the so called quantum bits could be read without disturbing their state.
    Which would either break quantum theory, or would mean they are just fabricated bits of information and not quantum bits at all.

    The article was here [slashdot.org]
  • by baldass_newbie (136609) on Friday December 02, 2005 @06:07AM (#14164675) Homepage Journal
    "God, what's a qubit?"
  • Que? (Score:5, Interesting)

    by Rhinobird (151521) on Friday December 02, 2005 @06:07AM (#14164677) Homepage
    A qubyte with eight ions provides a computing matrix of 65536 mostly independent elements.


    Wouldn't a qubyte just provide an indeteminate number of somewhere between 0 and 255 zombie cats?

    Seriously, how do they get a 16 bit number out of an 8 bit qubyte?
    • Re:Que? (Score:4, Informative)

      by L0phtpDK (711021) on Friday December 02, 2005 @06:16AM (#14164697)
      Umm... No.

      One qubit has four states. So its actualy an 8-qubit integer.

      (go through the powers of x^4: 4,16,64,256,1024,4096,16384,65536)
      • Re:Que? (Score:4, Insightful)

        by marol (734015) on Friday December 02, 2005 @06:23AM (#14164715)
        Don't you mean 4^x?
      • Is there someplace with more info? Because, nowhere in the article does it state that a qubit is 4 state. Just says that a qubit is quantum bit, and wikipedia [wikipedia.org] seems to think that a qubit is 2 state.
        • Re:Que? (Score:5, Interesting)

          by milimetric (840694) on Friday December 02, 2005 @09:59AM (#14165651) Journal
          I've read the posts here and I can point you to one source that I know is accurate, easy to understand and in my opinion beautiful:

          N. David Mermin [cornell.edu]

          This man is a genius. He can also explain his genius which makes him quite unique. I took a class of his and actually understood some stuff. His basic goal is to explain quantum computation to CS students. More on topic, here's the skinny on qubits:

          Chapter 1 of his intro class [cornell.edu]

          I really wouldn't do justice to the ease with which he explains things to attempt to summarize, but hey, what's slashdot for:

          Basically skip ahead to part C if you want to jump right into it. It helps if you think of Classical bits as vectors in a two dimensional space. (0,1) and (1,0) would represent 0 and 1 as we normally think about them. So then think about Quantum bits (qubits) as (a,b) which is just a superposition of the two classical bits with amplitudes a and b which are complex scalars. The only condition is that the qubit is a unit vector in two dimensional complex vector space, or in short |a|^2 + |b|^2 = 1. Now more to the point of this thread, if you go to section 1..62 you can see that n qubits make up a computational basis (or classical basis). So, the answer is, there's not really anything like simple 0,1 states for qubits. The truth is more complicated but once you start looking at how to take advantage of qubits, a lot more beautiful in my oppinion.
      • Re:Que? (Score:3, Informative)

        by Ruberik (935611)
        A qubit has an uncountably infinite number of states: choose any two complex numbers A and B such that |A|^2 + |B|^2 = 1, and they define an allowed qubit. On the other hand, when you measure a qubit's state, you can get one of two results: 0 (with probability |A|^2) or 1 (with probability |B|^2).

        I can't find the original article, so I don't know where this 2^16 business is coming from, but I assure you that a qubit does not have four states -- the only useful numbers for counting a qubit's number of state
        • So, (Score:3, Funny)

          by 2names (531755)
          When do we get an Improbability Drive?
        • The paper appears to be available here [nature.com].

          I eagerly await your analysis, seeing as I understand about 10% of the abstract.
      • A qubit does not have four states. As I have no idea what rabbit-hole you have pulled this notion from so I can't really figure out what your error is. A qubit is described by an element in a 2D complex vector space. The basis for this vector space has size two and the basis elements are often labelled |up> and |down>. So at a stretch you might say a qubit has two states. More accurately it has a countably infinite number of states. Maybe you have seen states like |left> and |right> written dow
      • One qubit has four states.

        If a qubit has four states instead of two, shouldn't we update Schroedinger's thought expirement to have four states? The cat is either: Dead, Not-Dead, Really-Not-Enjoying-Life, or Pining.

        • No, the four possible states are:
          1. The mechanism was triggered, and the cat is dead.
          2. The mechanism was triggered, but the cat survived the poison.
          3. The mechanism was not triggered, and the cat is alive.
          4. The mechanism was not triggered, but the cat died anyway.
    • Wouldn't a qubyte just provide an indeteminate number of somewhere between 0 and 255 zombie cats?

      Correct. What was meant here is that the unitary matrix describing the evolution of the system has N^2-1 independent entries. For the qubits, they simply used two different eigenstates of the Calcium ions as described in their paper in Nature [nature.com].
  • Mostly independent? (Score:3, Informative)

    by Rob Kaper (5960) on Friday December 02, 2005 @06:09AM (#14164678) Homepage
    The phrase "mostly independent" doesn't sound completely reliable to me in a world where a single 0 or 1 can change the entire meaning of data or functionality of software.

    Still, with some engineering experience it's easy to fill in what the article omits. Science moved forward and technology implementations will catch up and find a way to overcome issues like these. In fact, some data mirroring with checksums might already be more than sufficient and quantum particles offer sufficient improvements in data/space ratios that duplication should not be a concern.
  • Getting there... (Score:5, Interesting)

    by meringuoid (568297) on Friday December 02, 2005 @06:10AM (#14164682)
    ... Eight qubits? ISTR that Shor's original quantum error correction code requires nine, and there are simpler codes requiring fewer. We're getting here into a scale where some very interesting features of quantum computation can be demonstrated.
  • Why eight? (Score:5, Interesting)

    by pubjames (468013) on Friday December 02, 2005 @06:10AM (#14164684)
    Why did they choose eight 'bits' for their quantum 'byte'? For historical reasons, or is there a logical reason to choose eight? Why not seven, or 42?

    I'm not being entirely frivolous - I understand quantum computing is radically different from today's architectures and so don't understand why they are choosing a byte size based on what seems to me to be historical factors.
    • Re:Why eight? (Score:2, Informative)

      by grimJester (890090)
      Likely they've tried to get as many bits as possible and just now reached eight. Since eight bits are a byte, eight bits are a newsworthy milestone.
      • I believe the point the parent was trying to make is that eight bits aren't always a byte. (This is why so many standards use "octet stream".)

        A byte *typically* (indeed, virtually universally now) consists of eight bits, but there have been architectures with different values.

        See http://catb.org/~esr/jargon/html/B/byte.html [catb.org] for more information.
    • by glwtta (532858) on Friday December 02, 2005 @08:26AM (#14165093) Homepage
      Why did they choose eight 'bits' for their quantum 'byte'?

      They probably felt that 7 wasn't enough and 9 was too many.

    • Re:Why eight? (Score:3, Informative)

      by akaina (472254) *
      AFAICT, a byte denotes 8 identifiable positions (not to be confused with states). Each position has traditionally had 2 possible states. If quantum theory allows 4 states per position a qubyte can have 65536 permutation states.
    • Powers of two will continue to be significant. It still shows up in algorithms (eg, the quantum fast Fourier transform).
    • Re:Why eight? (Score:3, Interesting)

      by cev (572524)
      The work presented in the Nature article represents an incremental step towards applied quantum computing. There is no mention of "byte" in the Nature article. I suspect that the use of "byte" in the linked article is an abstraction created by a semi-technical promotional writer.

      The primary interest of the result is demonstration of the fidelity of 6, 7, and 8 particle entanglements. No applied computing is done, nor is there any particular reason why they stopped at eight particles except that it appears t
  • 1) Are they certain?
    2) What do qbit bytes taste like?
    3) So is this cat dead or what?
    • Flavours are easy. Up, Down, Sideways, Sex Appeal or Peppermint.

      (Apologies to Mr. Pratchett)
    • Re:Oblig (Score:3, Funny)

      by maxwell demon (590494)

      1) Are they certain?

      I guess they produced an eigenstate of the atom number operator, therefore they should be quite certain.

      What do qbit bytes taste like?

      That of course depends on what they are made of :-) Now it's very likely that their qubits only contain the traditional flavours up and down, because particles with strange flavour tend not to be very stabile.

      So is this cat dead or what?

      I just looked: It is dead. However, now I have problems with PETA activists from Copenhagen who claim I killed the cat by

  • by Renraku (518261) on Friday December 02, 2005 @06:50AM (#14164780) Homepage
    We need a few more before quantum porn.

    Think about it..any kind of porn in one file..
  • by Anonymous Coward on Friday December 02, 2005 @07:05AM (#14164813)
    Let us all take a minute to reflect on all the cats who died in support of this research.

    Or maybe they didn't.

  • by UncleAlias (157955) on Friday December 02, 2005 @07:08AM (#14164823) Homepage
    "That's not a bug, that's a quantum singularity!"
  • But... (Score:2, Funny)

    by cshank4 (917540)
    But will it run Linux?
  • by craznar (710808) on Friday December 02, 2005 @07:14AM (#14164842) Homepage
    ... build a Linux Box 40 Qubits in size....
  • by tcdk (173945) on Friday December 02, 2005 @07:18AM (#14164858) Homepage Journal
    Do we really need this? I can't imagine how anybody will have usage for more that four qubits anyway. When will the madness stop?
  • by mustafap (452510) on Friday December 02, 2005 @07:22AM (#14164865) Homepage
    My laymans understanding of quantum computing is that it will enable massively parallel calculations to occur simulataneously.

    The problem however is that you get all the answers simultaneously, and that the *real* problem is then finding efficient algorithms to search the results space.

    Could someone who actually knows what that all means dumb it down to our level, and explain how quantum computing will actually be useful?
    • by centie (911828) on Friday December 02, 2005 @07:40AM (#14164906)

      You've kind of answered your own question..

      The massive parrallel computation with a single element means you can solve *certain* problems in, for example, 2n instead of 2^n steps. But yes, then you get a bit matrix of answers, and reading them all out takes the same amount of steps as classical computing. But, your only usually intristed in some of the answers, so you can then use another algorithm (eg Deutsch-Jozsa) to read those out, again faster than classically.

      So you get a substantial decrease (ofton exponential) in the time taken to solve *cetain* problems. Some of these problems would simply be impossible to solve in any reasonable timescales (eg milennia) using classical algorithms.

    • Damn! That's easy!

      Quantum computing will become useful just about the time that Google's Search Engine becomes self-aware. Then the correct answer will be readily available and discernable from all the simultaneously calculated incorrect answers.

      Next question?
  • by putko (753330) on Friday December 02, 2005 @07:28AM (#14164876) Homepage Journal
    I found this at Caltech [caltech.edu], a piece on quantum computers. I've never really taken quantum computation seriously -- it just seemed too far-fetched. If they've really got 8-bits, maybe quantum computing will matter in my lifetime.

    From reading the piece, it sounds like we will have some major problems with our current cryptographic systems if quantum computers become available.
    • by gr8_phk (621180)
      AFAIK, the only problem QCs are good at solving is factoring (and the discrete logarithm problem which is equivalent). Does anyone know a complete list of problems they are supposed to be good for? I don't think it's very long. OTOH, research may provide more over time.
    • It's true that with a quantum computer you could easily break today's implementation of encryption but in theory quantum encryption will be unbreakable, even by other quantum computers, because of the nature of state in quantum mechanics. Although surely after the first quantum VPN it will only take a century or so to create some radically new type of computing that will break it. That is the nature of technology. Thank goodness for job security.
  • by digitaldc (879047) * on Friday December 02, 2005 @07:29AM (#14164882)
    "With a trap using magnetic fields they captured eight calcium ions, lined them up, and set up them in "W states" using a complicated laser technology"

    Calcium again coming to the rescue to provide structure for a complex system. What would people or quantum computers be without it?
  • From the "article": "This experiment proves that the kind of ion traps used in Innsbruck are the most promising technology for the realization of large computing matrices."

    This is the kind of press release with a primary message of "Dump huge buckets of cash HERE." No harm in that, Innsbruck needs to stump for research money like any University, but where do we find a comparitive check on _other_ technologies for realization of large computing matrices? The minimal description given of the Innsbuck de
  • FTA: With a trap using magnetic fields they captured eight calcium ions

    So, I guess floppy disks would be ruled out at this point.

  • yay! (Score:5, Funny)

    by 3-State Bit (225583) on Friday December 02, 2005 @07:51AM (#14164943)
    I was born in 1983, but now I can re-experience even advances in computing that happened in the seventies and before! Cabinet-sized hard-drives that hold a couple of megabytes? Quantum computing is at A FEW QUBITS! I doubt many people here lived through the ENIAC (and realized what it meant at the time), but that's exactly what my grandchildren will be hearing from me. Granson, back in my day we had EIGHT QUBITS! Not qubytes, QUBITS, sonny boy, eight of 'em. Like this: one, two, three, four, five, six, seven, eight. Total. And that was state of the art. It was a research demonstration! And we liked it!

    "There is a world market for 4, maybe 5 quantum computers."

    "512 kiloqubytes outta' be enough for anybody!"

    Etc, etc, etc. WHOOOHOO!!! I was there at ground zero, baby!!! In ought six!!!!

    What do you mean ought-six, grandpa? "I mean 2006, granson".

    "Whoa! When were you born?"

    "I was born in the LAST MILENNIUM, GRANSON"

    "Did they have cars?"

    "Just road ones."

    "What about Google?"

    "yeah, but it wasn't like today. Man I wish I'd have held on to that stock tho'..."
    • by mangu (126918)
      Cabinet-sized hard-drives that hold a couple of megabytes?


      Well, I have a Byte magazine from around the time you were born with an ad showing a photo of a man pushing a cabinet-sized box out of a bank safe. The text says something about "your first million". It was the first hard disk with a megabyte capacity priced under $5000 (of course, $4999 *is* less than $5k...)

    • I thought it was still ought-five.
  • No word? (Score:3, Funny)

    by Syberghost (10557) <syberghostNO@SPAMsyberghost.com> on Friday December 02, 2005 @08:20AM (#14165073) Homepage
    Actually, there was an announcement, but they used their qubit to crack your ssh key in five seconds and deleted it from your email.
  • A qubyte with eight ions provides a computing matrix of 65536 mostly independent elements.

    What does it mean by computing matrix and independent elements? Any Slashdotters familiar with the terms?
    • Frankly, it's garbage.

      The set of states of a qubit is essentially given by a 2 dimensional complex vector space. The set of pure quantum states of a qubyte (8 qubits) is given by a 256 dimensional complex vector space. Despite being fairly familiar with quantum computing I've no idea what a computing matrix is and I don't know where the 65536 is coming from. I guess I could pay the money and read the Nature article. But right now this looks like science journalism at its worst - just random keywords throw

  • Scalability (Score:3, Insightful)

    by Darius Jedburgh (920018) on Friday December 02, 2005 @09:59AM (#14165654)
    People have been expecting quantum computing to take off in a big way but after a couple of decades of research we still have only machines with a handful of qubits. I claimed from day one that the difficulty of building a quantum computer with memory N goes up exponentially. Because of Moore's law type effects our ability to build computers goes up exponentially. The net result is that I expect the memory of quantum computers to go up linearly over time, not exponentially like classical computers. I think we're seeing this borne out over the years. So don't expect quantum algorithms to crack codes any time soon. For what it's worth, I think the claims of scalability in the article are BS - but we'll see...
  • by abb3w (696381) on Friday December 02, 2005 @10:22AM (#14165832) Journal
    The initial report of IBM deploying a 7-qbit quantum computer came out December 19, 2001 [ibm.com]. The 8-qbit result from TFA was first reported (from a Google News search [google.com]) November 30, 2005-- roughly four years [timeanddate.com]. This gives a doubling period of roughly 20 years (7485 days).

    Which means there should be a 16 qbit machine by 2025, the 32 qbit machine by 2045... hmm. How unhelpful.

    • Maybe I've missed it, but don't you have to figure the curve also including how long it took to go from 1 qubit to 2, and 2 to 3, etc.?

      We had 2 qubits in 1998, 3 in 1999, and 5 in 2000 according to IBM [ibm.com].

      So, if you plot these, it looks like we've gone through an s-shaped growth curve where we'll never get much past 9 qubits. Here's the plot. [blogspot.com]

      RSA is safe now...

  • Does this mean there will be more than just 1s and 0s when it comes to things? Will there be more complex things going on?
    • Does this mean there will be more than just 1s and 0s when it comes to things?

      Yes. But only as long as you don't look at it. Seriously.

      Will there be more complex things going on?

      Yes. It's called superposition and entanglement. In some sense, the qubit can be 0 and 1 at the same time (well, that's very much simplified, but you get the idea). Which means you can effectively do the same calculation on all possible inputs at once (this is called quantum parallelism). For example, if you have a function f which

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