Abstract
We study the interconversion of multipartite symmetric -qubit states under stochastic local operations and classical communication (SLOCC). We demonstrate that if two symmetric states can be connected with a nonsymmetric invertible local operation (ILO), then they belong necessarily to the separable, W, or Greenberger-Horne-Zeilinger (GHZ) entanglement class, establishing a practical method of discriminating subsets of entanglement classes. Furthermore, we prove that there always exists a symmetric ILO connecting any pair of symmetric -qubit states equivalent under SLOCC, simplifying the requirements for experimental implementations of local interconversion of those states.
- Received 14 August 2009
DOI:https://doi.org/10.1103/PhysRevA.81.052315
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