Quantum Computer

Jump to navigation Jump to search

A Quantum Computer is a computing device that makes direct use of quantum-mechanical phenomena (such as superposition and entanglement).



  • CHRISTOPHER MONROE. (2019). “Quantum Computing is a Marathon not a Sprint." APRIL 21, 2019
    • QUOTE: Ordinary computers think in certainties, digitizing every aspect of the world to well-defined numbers. Quantum computers probe all possibilities, constantly updating the probabilities of multiple scenarios. Add more qubits, and they can consider exponentially more scenarios. A quantum computer is programmed to consider all these possibilities and narrow them down to just a few, and then when the output is measured, it can tell us information about all those scenarios. It is critical that a quantum computer not be measured or looked at while it considers the uncountable number of possibilities. For that reason, qubits are like senators before a controversial vote: They shouldn’t reveal their position until they are forced to. ...

      bank might use a quantum computer to estimate how much money you will have in your account a year from now, based on the probability you will get a raise or get fired, whether your teenager will crash the car, if the stock market will crash, and how these factors interact. ...

      In 3-5 years, these machines will perform certain calculations that would not be possible using ordinary computers. But it may be 5-10 years before any of these machines have the capacity and accuracy to solve useful problems. ...




  • http://en.wikipedia.org/wiki/Quantum_computer
    • A quantum computer is a computation device that makes direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from digital computers based on transistors. Whereas digital computers require data to be encoded into binary digits (bits), quantum computation uses quantum properties to represent data and perform operations on these data.[1] A theoretical model is the quantum Turing machine, also known as the universal quantum computer. Quantum computers share theoretical similarities with non-deterministic and probabilistic computers. One example is the ability to be in more than one state simultaneously. The field of quantum computing was first introduced by Yuri Manin in 1980[2] and Richard Feynman in 1981.[3][4] A quantum computer with spins as quantum bits was also formulated for use as a quantum space-time in 1969.[5]

      Although quantum computing is still in its infancy, experiments have been carried out in which quantum computational operations were executed on a very small number of qubits (quantum bits).[6] Both practical and theoretical research continues, and many national governments and military funding agencies support quantum computing research to develop quantum computers for both civilian and national security purposes, such as cryptanalysis.[7]

      Large-scale quantum computers will be able to solve certain problems much faster than any classical computer using the best currently known algorithms, like integer factorization using Shor's algorithm or the simulation of quantum many-body systems. There exist quantum algorithms, such as Simon's algorithm, which run faster than any possible probabilistic classical algorithm.[8] Given sufficient computational resources, a classical computer could be made to simulate any quantum algorithm; quantum computation does not violate the Church–Turing thesis.[9] However, the computational basis of 500 qubits, for example, would already be too large to be represented on a classical computer because it would require 2500 complex values (2501 bits) to be stored.[10] (For comparison, a terabyte of digital information is only 243 bits.)

  1. "Quantum Computing with Molecules" article in Scientific American by Neil Gershenfeld and Isaac L. Chuang
  2. Manin, Yu. I. (1980) (in Russian). Vychislimoe i nevychislimoe [Computable and Noncomputable]. Sov.Radio. pp. 13–15. http://publ.lib.ru/ARCHIVES/M/MANIN_Yuriy_Ivanovich/Manin_Yu.I._Vychislimoe_i_nevychislimoe.(1980).%5Bdjv%5D.zip. Retrieved 4 March 2013. 
  3. Feynman, R. P. (1982). "Simulating physics with computers". International Journal of Theoretical Physics 21 (6): 467–488. doi:10.1007/BF02650179. 
  4. Deutsch, David (1992-01-06). "Quantum computation". Physics World. 
  5. Finkelstein, David (1969). "Space-Time Structure in High Energy Interactions". In Gudehus, T.; Kaiser, G.. Fundamental Interactions at High Energy. New York: Gordon & Breach. 
  6. New qubit control bodes well for future of quantum computing
  7. Quantum Information Science and Technology Roadmap for a sense of where the research is heading.
  8. Simon, D.R. (1994). "On the power of quantum computation". Foundations of Computer Science, 1994 Proceedings., 35th Annual Symposium on: 116–123. doi:10.1109/SFCS.1994.365701. ISBN 0-8186-6580-7. 
  9. Nielsen, Michael A.; Chuang, Isaac L.. Quantum Computation and Quantum Information. p. 202. 
  10. Nielsen, Michael A.; Chuang, Isaac L.. Quantum Computation and Quantum Information. p. 17.