Operational Families of Entanglement Classes for Symmetric $N$-Qubit States

T. Bastin, S. Krins, P. Mathonet, M. Godefroid, L. Lamata, E. Solano

Published 2009-02-18, updated 2009-09-02Version 3

We solve the entanglement classification under stochastic local operations and classical communication (SLOCC) for all multipartite symmetric states in the general $N$-qubit case. For this purpose, we introduce 2 parameters playing a crucial role, namely the \emph{diversity degree} and the \emph{degeneracy configuration} of a symmetric state. Those parameters give rise to a simple method of identifying operational families of SLOCC entanglement classes of all symmetric $N$-qubit states, where the number of families grows as the partition function of the number of qubits.