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Local invariants for multi-partite entangled states allowing for a simple entanglement criterion

Hans Aschauer·John Calsamiglia·Marc Hein·Hans J. Briegel
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Abstract

We present local invariants of multi-partite pure or mixed states, which can be easily calculated and have a straight-forward physical meaning. As an application, we derive a new entanglement criterion for arbitrary mixed states of $n$ parties. The new criterion is weaker than the partial transposition criterion but offers advantages for the study of multipartite systems. A straightforward generalization of these invariants allows for the construction of a complete set of observable polynomial invariants.

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Hans Aschauer, John Calsamiglia, Marc Hein, Hans J. Briegel. 2004-08-03. Local invariants for multi-partite entangled states allowing for a simple entanglement criterion. https://arxiv.org/abs/quant-ph/0306048

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