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Multipartite entanglement in 2 x 2 x n quantum systems

Akimasa Miyake·Frank Verstraete
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Abstract

We classify multipartite entangled states in the 2 x 2 x n (n >= 4) quantum system, for example the 4-qubit system distributed over 3 parties, under local filtering operations. We show that there exist nine essentially different classes of states, and they give rise to a five-graded partially ordered structure, including the celebrated Greenberger-Horne-Zeilinger (GHZ) and W classes of 3 qubits. In particular, all 2 x 2 x n-states can be deterministically prepared from one maximally entangled state, and some applications like entanglement swapping are discussed.

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Akimasa Miyake, Frank Verstraete. 2004-01-07. Multipartite entanglement in 2 x 2 x n quantum systems. https://doi.org/10.1103/physreva.69.012101

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