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Quantum computer

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quantum computer is the most interesting topic in the computer science .

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Quantum computer

  1. 1. Quantum computer Prepared by Mohammad Ghorbani University of Arak 2015
  2. 2. Overview  Introduction  History  How quantum computer working?  Classical computer  Quantum computer  Applications of quantuum computer  Questions
  3. 3. Introduction  Waht is quantum computer?  What is quantum mechanic?  Whay quantum mechanic?
  4. 4. History of quantum computer  Yuri Manin (1937-he is still alive) He is russian-german mathematicion . In 1980 he was first to propose the idea of quantum computing.  Richard Feynmann(1918-1988) He was american theoretical phisicist . in 1981 he presented a Logical quantum computer model .
  5. 5. Classical computer A classical computer performs operations using bits wich can be either zero or one.
  6. 6. Quantum computer There are number of phisical objects that can be used as the qubit , a single photon or a electron. But how this work ? Well , all electrons have magnetic field , so they are basically like tiny bar magnetic and this property is called spin.
  7. 7. Quantum computer
  8. 8. Quantum computer In quantum world particles like electron are actually spinnning in all directions at a same time and this is one of the wierd aspects of quantum mechanics this type of phenomenon called superposition . We may measure by a measurement of an electron and find it’s spinning in a direction but before we did the measurement it was spinning in other ways at a same time. All at the same time ! Sounds crazy but true. So what this mean ? It means that electrons can spinning in many different directions at a same time and they can doing many computations at a same time!
  9. 9. Quantum computer In contrast quantum computer uses quantum bits or qubits and they can be both zero and one at the same time .interesting huh?
  10. 10. Quantum computer I guess that you are confused like me and others in first time so let’s consider the example of all possible combinations of 2-bit data system . We have 4 possible states.
  11. 11. A 2-bit classic computer can perform just one of these four possible functions simultaneosly and in order to check all of them, the computer would have to repeat each operation seperately. A 2-bit quantum computer due to the phenomenon of superposition is able to analyze all of possibilites at the same time in one operation!
  12. 12. comparsion So 2qubits contain information about four sates while 2bits only contain information about one satate! Thus a machine with n qubits can perform 2^n functions in a same time . A 4-qubits computer could analyze 16 states in a single operation in comparison a 4-bits classical computer can only analyze one state!
  13. 13. Are you still confused? Don’t be afraid! This is quantum mechanics nature .“No, you’re not going to be able to understand it. . . . You see, my physics students don’t understand it either. That is because I don’t understand it. Nobody does. ... The theory of quantum electrodynamics describes Nature as absurd from the point of view of common sense. And it agrees fully with an experiment. So I hope that you can accept Nature as She is -- absurd.” Richard Feynman
  14. 14. Ok . Why we need quantum computer?Becuase there are problems in our world that even fastest supercomputer can’t solve them in optimal time. Let me give you some example. Problem : a salesman has to travel to many cities and want to work out the shortest possible route? That sounds like an easy problem! For 14 cities a classical 1GHz it would take 100 seconds. But happens for 22 cities? It would take 1.600 years! And for 28 cities it’s longer than the lifetime of the universe.
  15. 15. Applications of quantum computer Quantum computer give us a power that we can solve issues that deal with enormous data. Indeed it can deal with enormous data and proccess it. Let me give you some examples.  Discover distant planet  Detect cancer earlier  Develop more effective drugs  Predicting weather  And so more....
  16. 16. D-wave quantum computer
  17. 17. D-wave quantum computer
  18. 18. D-wave quantum computer
  19. 19. D-wave quantum computer
  20. 20. Questions
  21. 21. Thank You

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