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Entanglement for a two-parameter class of states in $2\otimes n$ quantum system

Dong Pyo Chi·Soojoon Lee
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Abstract

We exhibit a two-parameter class of states $ρ_{(α,γ)}$, in $2\otimes n$ quantum system for $n\ge 3$, which can be obtained from an arbitrary state by means of local quantum operations and classical communication, and which are invariant under all bilateral %unitary operations %of the form $U\otimes U$ on $2\otimes n$ quantum system. We calculate the negativity of $ρ_{(α,γ)}$, and a lower bound and a tight upper bound on its entanglement of formation. It follows from this calculation that the entanglement of formation of $ρ_{(α,γ)}$ cannot exceed its negativity.

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Dong Pyo Chi, Soojoon Lee. 2003-09-09. Entanglement for a two-parameter class of states in $2\otimes n$ quantum system. https://doi.org/10.1088/0305-4470/36/45/010

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