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Nanotechnology and Quantum Computing

  1. Dec 17, 2005 #1
    Where do these fields overlap (if at all) and where do they differ?

    If one was doing Nanotechnology at the graduate level with a BSc in physics behind them, what kinds of courses would one be taking? What about for Quantum Computing?
  2. jcsd
  3. Dec 18, 2005 #2
    I asked my physics advisor the same thing at the beginning of the school year. Quantum computing is a broad field, there's the mathematics and theoretical computer science to it, the physics of course, and much more. Where nanotechnology and QC overlap is the area where the attempts to "build" ones occur. The progress in that area, I do not know.
  4. Dec 18, 2005 #3
    I would not say that. QC is the implementation of the principles of QM into software programming. Check out John Preskill's webpage for more info on this

    Nanotechnology and QC do not overlap. Nanotechnology is just another name for quantum many body physics/chemistry on the micro/nano-distance scale.

  5. Dec 18, 2005 #4
    The main goal of quantum computing may not be broad, but if somebody says that their research is quantum computing, that doesn't tell you much about what exactly it is they are researching. The field of quantum computing consists of many areas. You can't disagree with that.
  6. Dec 18, 2005 #5
    Name me five such areas, please.

  7. Dec 18, 2005 #6

    quantum algorithms
    quantum information theory
    quantum cryptography
    quantum error-correcting codes
    quantum teleportation (tangentially)

    Or, if you're an experimentalist:

    Trapped ion qubits
    NMR qubits
    Exciton qubits
    Optical cavity qubits
    Cavity QED qubits

  8. Dec 18, 2005 #7
    :rolleyes: Typical...

    I am sorry but this is all dual. QIT is about cryptography and so on...and on...and on...

    When one speaks of QM, one does not address each single topic of QM separately.

    All the things you mentioned are QM, "point final"...
    Just check out how John Preskill's course is constructed and you will se why all these topics are "dual" to one and other.

    This is just QM, well many body QM to be exact.

    Last edited: Dec 18, 2005
  9. Dec 18, 2005 #8
    QED is just QM?

    Anyway, I listed five experimental approaches to qubits - afaik they pretty much don't intersect at all, they're five orthogonal subfields. If they're "just QM", then so is all of condensed matter theory.
  10. Dec 18, 2005 #9
    Great link, thanks!
  11. Dec 18, 2005 #10
    When did i ever say that ?

    this is really not true. Error correction is constantly used in encryption and well, the quantum algorithms are the basic ingredient of error correction, encryption,...I mean, we are dealing with "software" here. Do not forget that.

  12. Dec 18, 2005 #11
    Yeah, but I was referring to the experimental part - the NMR vs. Ion trap vs. optical cavity... they're all different experimental groups, and I doubt they corroborate much.

    Though apparently you're right about the theory part, it's essentially a single field.
  13. Dec 18, 2005 #12
    You were ? Than you should have been more clear. Anyhow, NMR has nothing to do with quantum information technology. It is a technique that might be used for the practical implementation of some of the QIT aspects (encryption, entanglement,...). The same story holds for all the rest.

    Also, i never said that QED is QM or something of that nature. All i ever said was that the theory behind your second list comes from many body physics (of which condensed matter is a subfield).

    Besides, if you are talking about "cavity QED qubits" you should be very sure what this is about. I means i could ask you these two questions :

    1) The epitheton "QED" implies that you need QED in this case. Hence one can no longer talk about quantum information technology, since this field is defined as the implementation of QM into software algorithm development (again i refer to John Preskill's webpage for this).

    2) Why exactly do you need QED here ? Why no ordinary QM many body physics ? Or is it that you do not really need QED, but QED is "just" a part of the name ?

  14. Dec 18, 2005 #13
    I don't actually know any QED (:frown:), but I believe the cavity QED qubit involves an atom strongly coupled to a photon in an optical cavity, or something, so yes QED is needed.

    NMR has nothing to do with quantum information theory, but if you're talking about quantum computing - which is a practical thing, not the same as theoretical computer science - then it has everything to do with that. The group that implemented Deutsch's algorithm a few years ago, they were using NMR.

    But this is getting semantical...
  15. Dec 18, 2005 #14
    Yes but this is my point. It is a technique that is used in QIT, but it is NOT a result of QIT. That is the big difference i am trying to illustrate here.

    Again, Deutsch's problem is a direct result from coming from QIT (ie the implementation of QM-principles in actual algortihms) but NMR is just used here as an experimental technique. NMR itself is a QM's thing.

  16. Dec 18, 2005 #15
    To clarify: the original post used the words "quantum computing", so I assumed the topic was the most general one, inclusive of the pragmatic, experimental stuff. Regarding QIT, we seem to agree about what it means.

    [/semantics war]
  17. Dec 18, 2005 #16
    <semantics war>

    Request for clarification : what does the content of your above post has got to do with our discussion ?


    </semantics war>
  18. Dec 18, 2005 #17
    <semantics war>

    I wasn't talking about NMR in general, I was referring to the use of NMR and radio-pulses to experimentally implement some aspects of quantum computing. The use of nuclear spin qubits in NMR is a significant research area in (experimental) quantum computing. At the same time, you were talking about quantum information theory, which is... information theory (with QM). The disconnect was that I thought you thought NMR qcomputing wasn't important, and you thought I thought NMR was somehow a theoretical aspect of quantum information. Hence this ongoing semantics war.

    </semantics war>
  19. Dec 18, 2005 #18
    A computer does computation. It's an physical implementation of certain information-theoretic abstractions. But "computation" != "information theory".
  20. Dec 18, 2005 #19
    Doesn't quantum computing require working at the atomic level for quantum effects? Is this not "nano"?
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