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UConn Physics Colloquium
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Quantum Machines: Cloners and Their Relatives
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Mark
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Hillery
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Hunter College
City University of New York
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Quantum information is information stored in quantum systems. The ways in which it can be manipulated are determined by quantum instead of classical physics. This produces some surprises. Quantum information cannot be exactly copied, which makes it useful for cryptography. It can, however, be approximately copied, and the devices that do so are called quantum cloners. Another device, which turns out to be closely related to cloners, flips the state of an incoming quantum bit (qubit for short), a two-level quantum system, to the state orthogonal to the input state. This also cannot be done exactly, but can be done approximately. Cloners and spin-flippers are single purpose devices, but it is also possible to construct quantum machines that can perform many different operations, with the choice of operation dictated by a program, which is itself a quantum state. |

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Friday, October 1, 2004
4:00 PM
Gant Science Complex
Physics Department
Room P38
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(We will meet for refreshments prior to the talk at 3:30 p.m., in the Gant Science Complex, Physics Library, Room P-103.)

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