Geometric measure of entanglement and applications to bipartite and multipartite quantum states

@article{Wei2003GeometricMO,
  title={Geometric measure of entanglement and applications to bipartite and multipartite quantum states},
  author={Tzu-Chieh Wei and Paul M. Goldbart},
  journal={Physical Review A},
  year={2003},
  volume={68},
  pages={042307}
}
The degree to which a pure quantum state is entangled can be characterized by the distance or angle to the nearest unentangled state. This geometric measure of entanglement, already present in a number of settings [A. Shimony, Ann. NY. Acad. Sci. 755, 675 (1995); H. Barnum and N. Linden, J. Phys. A: Math. Gen. 34, 6787 (2001)], is explored for bipartite and multipartite pure and mixed states. The measure is determined analytically for arbitrary two-qubit mixed states and for generalized Werner… 

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