We consider an assembly of N indistinguishable two-level atoms, for which a concept of spin- squeezing and entanglement measures can be well defined. Permutation symmetry of such a state allows one to use an entanglement measure called the concurrence as the measures of pairwise and also N-partite entanglement. Dy using these measures, we show that negative pair-spin correlations of the state are quantum ones. It implies the quantumness of a spin-squeezing, which also possesses pair-spin negative correlations. We also provide the entanglement measures of a macroscopic entangled state and an atomic Dicke state for super-radiant and spontaneous emissions.We consider an assembly of N indistinguishable two-level atoms, for which a concept of spin- squeezing and entanglement measures can be well defined. Permutation symmetry of such a state allows one to use an entanglement measure called the concurrence as the measures of pairwise and also N-partite entanglement. Dy using these measures, we show that negative pair-spin correlations of the state are quantum ones. It implies the quantumness of a spin-squeezing, which also possesses pair-spin negative correlations. We also provide the entanglement measures of a macroscopic entangled state and an atomic Dicke state for super-radiant and spontaneous emissions.

Физик сэтгүүлMar 13, 20220 citations

Spin squeezing, negative correlations, and concurrence in the quantum kicked top model

Xiaoqian Wang, Jian Ma, Lijun Song +2 more

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.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.

arXiv:1010.0109Physical Review ENov 12, 201015 citations

Quantum phases and entanglement properties of an extended Dicke model

Michal Kloc, Pavel Stránský, Pavel Cejnar

arXiv:1609.02758Annals of PhysicsApr 29, 201733 citations

New entanglement properties in systems of higher-spin particles

Jay Lawrence, Mario Gaeta, Andrei Klimov

Bulletin of the American Physical SocietyFeb 27, 20120 citations

Constructions of Dicke states in high spin multi-particle systems

Wanfang Liu, Zheng-Da Hu

We study the constructions of Dicke states of identical particles of spin- $1$ , $3/2$ and $2$ in the number representation with given particle number $N$ and magnetic quantum number $M$ . The complete bases and corresponding coefficients in the Dicke states are given, in terms of which the Dicke states are explicitly expressed in the number representation. As a byproduct, a rule of how to construct all the anti-symmetric states in these high spin systems is given. Finally, by employing the negativity as the entanglement measure, we explore the entanglement properties for spin- $1$ cases including certain pure states of two particles and many-particle Dicke states.We study the constructions of Dicke states of identical particles of spin-$1$, $3/2$ and $2$ in the number representation with given particle number $N$ and magnetic quantum number $M$. The complete bases and corresponding coefficients in the Dicke states are given, in terms of which the Dicke states are explicitly expressed in the number representation. As a byproduct, a rule of how to construct all the anti-symmetric states in these high spin systems is given. Finally, by employing the negativity as the entanglement measure, we explore the entanglement properties for spin-$1$ cases including certain pure states of two particles and many-particle Dicke states.

arXiv:1511.03281Nov 8, 20150 citations

We study the constructions of Dicke states of identical particles of spin-

1

3/2

and

2

in the number representation with given particle number

N

and magnetic quantum number

M

. The complete bases and corresponding coefficients in the Dicke states are given, in terms of which the Dicke states are explicitly expressed in the number representation. As a byproduct, a rule of how to construct all the anti-symmetric states in these high spin systems is given. Finally, by employing the negativity as the entanglement measure, we explore the entanglement properties for spin-

1

cases including certain pure states of two particles and many-particle Dicke states.