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arXiv · 0809.1932

Entanglement Measures for Intermediate Separability of Quantum States

Tsubasa Ichikawa·Toshihiko Sasaki·Izumi Tsutsui
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Abstract

We present a family of entanglement measures R_m which act as indicators for separability of n-qubit quantum states into m subsystems for arbitrary 2 \leq m \leq n. The measure R_m vanishes if the state is separable into m subsystems, and for m = n it gives the Meyer-Wallach measure while for m = 2 it reduces, in effect, to the one introduced recently by Love et al. The measures R_m are evaluated explicitly for the GHZ state and the W state (and its modifications, the W_k states) to show that these globally entangled states exhibit rather distinct behaviors under the measures, indicating the utility of the measures R_m for characterizing globally entangled states as well.

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Tsubasa Ichikawa, Toshihiko Sasaki, Izumi Tsutsui. 2009-04-06. Entanglement Measures for Intermediate Separability of Quantum States. https://doi.org/10.1103/physreva.79.052307

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