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Quantum Computing Using Traditional Transistors

Posted by CowboyNeal on from the reusing-old-hardware dept.

Ocean Consulting writes "UCLA is reporting progress on the quantum computing front by announcing success in controlling the spin of a single electron using an ordinary transistor." It's been a long road for the researchers involved, and even the project lead, Hong Wen Jiang admits, "...our initial theoretical calculations were very favorable, and gave us confidence to persevere."

13 of 323 comments (clear)

  1. Secure communications? by agm · · Score: 5, Insightful

    Quantum computing, which holds the promise of nearly unlimited processing power, secure communications and the ability to decode encrypted conversations by terrorists and others, is a significant step closer to becoming a reality today with new research published by a team of UCLA scientists in the journal Nature.

    So which is it, secure communications or communications that can be spied on? It can't be both.

    1. Re:Secure communications? by Christopher+Thomas · · Score: 2, Insightful

      Using a quantum computer it can search every possible key simultaneously, cracking the encryption almost instantly.

      My understanding was that this is not true. At best you get the square root of the number of steps that would be required for a non-quantum brute force search. This means that key sizes are effectively halved, but that isn't an insurmountable problem.

      A bigger problem is that some algorithms are intrinsically vulnerable to quantum computing (or to rephrase, take far, far fewer steps to reverse on a quantum computer than a classical one). Factoring is one such case, which is why quantum computing spells the death of RSA. Most other algorithms are relatively safe, if I understand correctly (or at least, have no known quantum computing cracking method beyond brute force; this may change, unless they're _proven_ to have no other cracking method).

      In summary, quantum computing is powerful, but not a magic wand that makes all classical encryption schemes invalid.

  2. Now that's a huge hard drive... by zeux · · Score: 3, Insightful

    From the article:
    "With 100 transistors, each containing one of these electrons, you could have the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around," Yablonovitch said. "And why stop with 100 transistors?"

    Of course, because with 101 transistors you could store as many Library of Congress as there are electrons in the visible universe on a disk the size of 2 square hogs for a duration of up to 3.4256 parsecs.

    Unfortunately, it will take up to as many (1/98742) of year as it took in seconds for Apollo 11 to reach the moon from the launch pad to design such a hard-drive.

    Why is it scientists always use weird units? I have absolutely no clue of what "the implicit information storage that corresponds to all of the hard disks made in the world this year, multiplied by the number of years the universe has been around" actually represents in bytes.

    --
    Iraq: war to save the U
  3. Re:wow! by geekoid · · Score: 3, Insightful

    "(Up'ing clockspeed constantly and decreasing chip size is not evolutionary.) "

    actually, it is evolutionary, just not revolutionary.

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    The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  4. Tin Foil Hat Time... by CommanderData · · Score: 4, Insightful

    From the article:
    Quantum computing, which holds the promise of nearly unlimited processing power, secure communications and the ability to decode encrypted conversations by terrorists and others (emphasis mine)

    Take special note of the word others, which should be read as everyone. The government will be falling all over themselves to support this research and inherit a technology that makes encryption virtually useless.

    I'm all for advancing technology, and no doubt quantum computing will be a great leap forward. It's just a shame that our privacy will be sacrificed in the process.

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    Urge to post... fading... fading... RISING!... fading... fading... gone.
    1. Re:Tin Foil Hat Time... by Anonymous Coward · · Score: 1, Insightful

      If you become a "person of interest," you have no privacy. Neither do you control if or when you become a person of interest. Some dipshit in your workgroup can do questionable things without informing you, yet you go under the microscope, guilty by association.

      One might argue that it would be better to live with an open kimono all the time. If everybody could know everything about you all the time, on demand, your whole life history from beginning to end in any format that might be desired, inside out and outside in, and you could know everything about anybody else...

      fortunately I will be dead before they work it out

  5. Secure Communications ... by mdvlspwn99 · · Score: 4, Insightful

    is great. Until the technology becomes ubiquitous enough that even terrorists have access to it. Then what? It's secure...even from us.

    --
    If reality was like Slashdot, most people would be (-1) Redundant.
  6. Bremermann's limit? by Anonymous Coward · · Score: 1, Insightful

    Does this have the potential to make Bremermann's limit obsolete or did he have the forsight to take this into account?

  7. Re:Awesome! by argent · · Score: 2, Insightful

    Don't be too impressed... it doesn't mean as much as it sounds.

    It's kind of like saying a room full of monkeys implicitly encode all the works of Shakespeare.

  8. Terrorists? by mikeg22 · · Score: 2, Insightful

    Oh, you mean the ones that use human couriers to relay messages? The ones that live in caves with no access to computers?

    No, this technology is not going to be used on terrorists. It is going to be used on a combination of normal people suspected of criminal activity (ie anyone who bothers to encrypt their communications) and actual hightech criminals.

    This technology will be effectively useless at stopping the terrorists we are worried about.

  9. Re:Terrorism. by emeitner · · Score: 3, Insightful

    Fear sells.

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    Guru Meditation #6d416769.21610a21
  10. Re:Why does anyone believe this works... by Requiem+Aristos · · Score: 2, Insightful

    *SMACK*

    This would be an accurate description, only it's not.

    If you perform the double-slit experiment with twenty humans, a canon, and segments of brick walls, you don't wind up with an interference pattern. With electrons, you do. Also, factoring with quantum computers has been successfully performed, so we know it works.

    If it makes you feel better, it isn't just a matter of treating statistics as physical reality. It's more a matter of realizing that at certain small sizes, 'matter' isn't exactly matter. It's closer to energy, and has a wave behavior similar to energy. It just happens that measurable physical properties can only be said to exist when the wave function has 'collapsed'.

    (I expect some QM geek will want to correct my explanation, but it's certainly more accurate than your attempt. Happy trolling!)

  11. Re:Kind of misleading... by QuantumG · · Score: 2, Insightful

    Well seeing as you can lay down a junction on a silicon die that can produce that microwave burst just as easily as you can lay down a transistor the basic principle that you can do quantum computing with silicon is still being demonstrated.

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    How we know is more important than what we know.