17,282 research outputs found
Local distinguishability of orthogonal 2\otimes3 pure states
We present a complete characterization for the local distinguishability of
orthogonal pure states except for some special cases of three
states. Interestingly, we find there is a large class of four or three states
that are indistinguishable by local projective measurements and classical
communication (LPCC) can be perfectly distinguishable by LOCC. That indicates
the ability of LOCC for discriminating states is strictly more
powerful than that of LPCC, which is strikingly different from the case of
multi-qubit states. We also show that classical communication plays a crucial
role for local distinguishability by constructing a class of
states which require at least rounds of classical
communication in order to achieve a perfect local discrimination.Comment: 10 pages (revtex4), no figures. This is only a draft. It will be
replaced with a revised version soon. Comments are welcom
Conditions for entanglement transformation between a class of multipartite pure states with generalized Schmidt decompositions
In this note we generalize Nielsen's marjoization criterion for the
convertibility of bipartite pure states [Phys. Rev. Lett \textbf{83},
436(1999)] to a special class of multipartite pure states which have
generalized Schmidt decompositions.Comment: 3 pages (Revetex 4), no figures. A brief note on entanglement
transformation. Comments are welcom
Optimal Simulation of a Perfect Entangler
A unitary operation is called a perfect entangler if it can
generate a maximally entangled state from some unentangled input. We study the
following question: How many runs of a given two-qubit entangling unitary
operation is required to simulate some perfect entangler with one-qubit unitary
operations as free resources? We completely solve this problem by presenting an
analytical formula for the optimal number of runs of the entangling operation.
Our result reveals an entanglement strength of two-qubit unitary operations.Comment: 4 pages, Comments are welcomed;v2 : more discussions with previous
related works, main results unchanged, submitted to PR
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