Concurrence and Foliations Induced by Some 1-Qubit Channels
نویسنده
چکیده
We start with a short introduction to the roof concept. An elementary discussion of phase-damping channels shows the role of anti-linear operators in representing their concurrences. A general expression for some concurrences is derived. We apply it to 1-qubit channels of length two, getting the induced foliations of the state space, the optimal decompositions, and the entropy of a state with respect to these channels. For amplitude-damping channels one obtains an expression for the Holevo capacity allowing for easy numerical calculations.
منابع مشابه
ar X iv : q ua nt - p h / 06 05 10 3 v 1 1 1 M ay 2 00 6 On Concurrence and Entanglement of Rank Two Channels
Concurrence and further entanglement quantifiers can be computed explicitly for channels of rank two if representable by just two Kraus operators. Almost all details are available for the subclass of rank two 1-qubit channels. There is a simple geometric picture beyond, explaining nicely the role of anti-linearity.
متن کاملar X iv : q ua nt - p h / 06 05 10 3 v 1 1 1 M ay 2 00 6 On Concurrence and Entanglement of Rank Two Channels ∗ Armin Uhlmann
Concurrence and further entanglement quantifiers can be computed explicitly for channels of rank two if representable by just two Kraus operators. Almost all details are available for the subclass of rank two 1-qubit channels. There is a simple geometric picture beyond, explaining nicely the role of anti-linearity.
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