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Quantum computers-the poll!


  1. NMR quantum computers

    4 vote(s)
  2. ion trap quantum computers

    6 vote(s)
  3. silicon quantum computers

    1 vote(s)
  4. other

    3 vote(s)
  1. Aug 2, 2004 #1
    quantum computers---the poll!

    Come on! This is your opportunity to influence in the future
    Quantum computation is advancing firmly, problems of the past have been solved thanks to Shor's code, and decoherence does not seem now such a big problem. What of these 3 techniques (or other) will be the used in the quantum computers of the future? Vote now! I will also appreciate some comments. The future of quantum computation depends on YOU

    PS: In fact a silicon quantum computer is a kind of NMR quantum computer, but the fact that is made of a solid make it differs from other liquid NMR quantum computers. So the 4 options are (in this order):
    1)liquid NMR quantum computers
    2)ion trap quantum computers
    3)silicon NMR quantum computers
    Last edited: Aug 2, 2004
  2. jcsd
  3. Aug 2, 2004 #2
    I still haven't seen a single (simple) example of how a quantum computer uses quantum mechanics to do anything useful. And it's not that I didn't ask. :cry:
  4. Aug 2, 2004 #3
    there are some quantum algorithms that surpass any of the capacities of classical algorithms, e.g.
    Shor's algorithm for factorization of prime numbers: it can really break down the widely used RSA public key cryptosystem
    Grover's algorithm: for searching a database
    Simon's algorithm: for find periods of functions
  5. Aug 3, 2004 #4
    They are going to use josephson's junctions on silicon. They will make quantum dots on islands, as they are, and use those for quantum computation.
  6. Aug 3, 2004 #5
    Is this the type of quantum computer known as "quantum dot quantum computer"?
    StealthC, you seem to know what you're talking about. Do you think that superconducting quantum computers do have a great future?
  7. Aug 3, 2004 #6
    Quantum-optics computer is important too?
  8. Aug 3, 2004 #7
    I heard that there's a proposal for a linear optical quantum computer, but not much info at google

    It seems that liquid NMR QC, the first option of the poll, it's a dead end path, the experts say that they will not be ever be capable of surpass the implantation of more than 10 qubits. It seems that the fight will be between the second and third option. Ion trap Quantum computers were invented in 1995 by Peter Zoller and the spanish Ignacio Cirac. Silicon quantum computers were first proposed in 1998 by Bruce Kane.

    There seems that there's some minor investigation in other device called Cavity QED quantum computer
    Last edited: Aug 3, 2004
  9. Aug 6, 2004 #8
    Could you please give me a simple example of a mechanism in which the quantum nature of qubits is used to do any calculation in a non-classical way? (Please write it here.)

  10. Aug 6, 2004 #9
    Re to salsero: Could you please give me a simple example of a mechanism in which the quantum nature of qubits is used to do any calculation in a non-classical way?
    I understand QuantumComputer and Quantum Computations as computation with quantum bits-Qubits. I think it is very simplest to understand but not simple to do. I think that Quantum Computer is a ansamble of quantum objects which prepare in the same spin states. It is named as inicialization. Spin up is 0 and itraverse 1. Before measurement we do not know the states of any objects and can say that it is the superposition of 1 and 0. Psi=a|0>+b|1>. In addition the all Quantum Objects (Qubits) as it is you known has the property of of Non-Locality. It is means in some words that all quantum objets are correlated i.e. has the same spin state. Before measurement it is Psi for the same qubit. From this follow that the all qubits is not interaction but has quantum correlation or in other words it is parralel. Thats all. Than how to copmutate with this device? Every qubit has not two states only but superposition Psi. When we use any qubit for computation then it is change in the process of computation and it is change the all qubits because its parralel. When we have the task of looking for the something than every qubits is looking for and in the same time to change other qubits!!! I suppose that somebody think that Quantum Competer is secret program because I do not see open information about job in area of QC.
  11. Aug 9, 2004 #10
    The simplest example to understand is the Deutsch-Jozsa algorithm. Get the details here:

  12. Aug 13, 2004 #11
    So I understand that there is no simple example. One cannot understand how quantum mechanics helps to the computation without considering details of some complicated algorithms...
  13. Aug 13, 2004 #12


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    What are those? I think I read somewhere that they needed high temperature superconductors to work...
  14. Aug 13, 2004 #13


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    Ohhh yes! Definitly.
  15. Aug 13, 2004 #14


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    What do these different types do and how are they diffrent? What does NMR stand for?

  16. Aug 13, 2004 #15
    Relax! It's more easy than it seems!

    NMR stands for Nuclear magnetic resonance. A liquid NMR QC is in fact a drop of some substance composed of a kind of molecule, so the number of atoms of each molecule of the substance that you are able to manipulate at the same time using NMR techniques gives the number of qubits of the computer. The record until today is a 7-qubit liquid NMR quantum computer
    About the silicon quantum computer, aka Kane quantum computer because was discovered by Kane, you can find info here
    Interestingly, the Deutsch-Jozsa algorithm was implemented last year in a ion trap quantum computer
    Last edited: Aug 13, 2004
  17. Aug 13, 2004 #16
    No, superconductor-based approaches would probably use niobium or, most likely, aluminium.
  18. Aug 13, 2004 #17
    I don't know why NMR is even on there; it will never work past a few tens of qubits, and that's if they're lucky.
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