منابع مشابه
Entanglement purification of unknown quantum states
A concern has been expressed that “the Jaynes principle can produce fake entanglement” [R. Horodecki et al., Phys. Rev. A 59, 1799 (1999)]. In this paper we discuss the general problem of distilling maximally entangled states from N copies of a bipartite quantum system about which only partial information is known, for instance in the form of a given expectation value. We point out that there i...
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The conformal factor of the spacetime metric becomes dynamical due to the trace anomaly of matter fields. Its dynamics is described by an effective action which we quantize by canonical methods on the Einstein universeR×S3. We find an infinite tower of discrete states which satisfy the constraints of quantum diffeomorphism invariance. These physical states are in one-to-one correspondence with ...
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The information encoded in a quantum system is generally spoiled by the influences of its environment, leading to a transition from pure to mixed states. Reducing the mixedness of a state is a fundamental step in the quest for a feasible implementation of quantum technologies. Here we show that it is impossible to "transfer" part of such mixedness to a "trash" system without losing some of the ...
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ژورنال
عنوان ژورنال: Physical Review A
سال: 2006
ISSN: 1050-2947,1094-1622
DOI: 10.1103/physreva.73.062309