Abstract
We describe a purely algebraic method for finding the best separable approximation to a mixed state of a composite quantum system, consisting of a decomposition of the state into a linear combination of a mixed separable part and a pure entangled one. We prove that, in a generic case, the weight of the pure part in the decomposition equals the concurrence of the state.
- Received 23 April 2001
DOI:https://doi.org/10.1103/PhysRevA.64.052302
©2001 American Physical Society