title: Spin squeezing, negative correlations, and concurrence in the quantum kicked top model.
abstract: We study spin squeezing, negative correlations, and concurrence in the quantum kicked top model. We prove that the spin squeezing and negative correlations are equivalent for spin systems with only symmetric Dicke states populated. We numerically analyze spin squeezing parameters and concurrence in this model and find that the maximal spin squeezing direction, which refers to the minimal pairwise correlation direction, is strongly influenced by quantum chaos. Entanglement (spin squeezing) sudden death and sudden birth occur alternatively for the periodic and quasiperiodic cases, while only entanglement (spin squeezing) sudden death is found for the chaotic case.
authors.affiliation: Department of Physics, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Wang
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.forename: Lijun
authors.initials: L
authors.lastname: Song
authors.forename: Xihe
authors.initials: X
authors.lastname: Zhang
authors.forename: Xiaoguang
authors.initials: X
authors.lastname: Wang