Spin squeezing and concurrence

Xiaolei Yin, Xiaoqian Wang, Jian Ma, Xiaoguang Wang

Published 2009-12-09, updated 2010-10-06Version 3

We study the relations between spin squeezing and concurrence, and find that they are qualitatively equivalent for an ensemble of spin-1/2 particles with exchange symmetry and parity, if we adopt the spin squeezing criterion given by the recent work (G. Toth et al. Phys. Rev. Lett. 99, 250405 (2007)). This suggests that the spin squeezing has more intimate relations with pairwise entanglement. We exemplify the result by considering a superposition of two Dicke states.