Quantum Correlation without Entanglement in a Two-Atom-Vacuum Field System

Quantum correlation without entanglement in a two-atom-vacuum field system is investigated. The influence of the atomic dipole-dipole interaction on quantum correlation is also examined. We find that, when both atoms are initially in separable excited states, the quantum discord of two atoms appears while their entanglement wholly vanishes throughout the evolution. We explain our results in detail Our results provide a novel method of achieving a quantum correlation resource without entanglement in the real system.     

简并拉曼过程中斯塔克位移对原子反转及场熵的影响

研究了考虑斯塔克（Ｓｔａｒｋ）位移的简并拉曼过程中原子与场的耦合特性及斯塔克位移对原子反转及场熵的影响。     

附加克尔介质Jaynes—Cummings模型场的位相特性

运用Pegg-Barnett厄米位相公式,研究了附加克尔(Kerr)介质Jaynes-Cummings(J-C)模型场的位相特性.具体讨论了场的位相概率分布、厄米位相算符的期待值以及位相的涨落,通过与标准J-C模型作比较,讨论了克尔介质与模场的非线性相互作用对场位相特性的影响.     

多光子Jaynes-Cummings模型场熵的演化

本文研究了多光子Jaynes-Cummings(J-C)模型场熵的演化性质、光场涨落的量度以及模型的有效性.     

依赖强度耦合的多光子Jaynes—Cummings模型场的位相特性

本文运用Pegg—Barnett位相理论,研究了依赖强度耦合的多光子Jaynes—Cummings模到场的位相特性,具体讨论了其位相概率分布、厄来位相算符的平均值以及位相的涨落。     

附加克尔介质Jaynes－Cummings模型的场熵演化

研究了附加克尔（Ｋｅｒｒ）介质Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ（Ｊ－Ｃ）模型场熵演化的动力学特性，讨论了克尔介质非线性相互作用以及失谐量对场熵演化的影响．     

Dynamics of quantum discord in a two-qubit system under classical noise

We study the quantum discord dynamics of two noninteracting qubits that are, respectively, subject to classical noise. The results show that the dynamics of quantum discord are dependent on both the coupling between the qubits and classical noise, and the average switching rate of the classical noise. In the weak-coupling Markovian region, quantum discord exhibits exponent decay without revival, and can be well protected by increasing the average classical noise switching rate. While in the strong-coupling non-Markovian region, quantum discord reveals slowly decayed oscillations with quick revival by decreasing the average switching rate of the classical noise. Thus, our results provide a new method of protecting quantum discord in a two-qubit system by controlling the coupling between the qubits and classical noise, and the average switching rate of the classical noise.     

附加克尔介质Jaynes—Cummings模型的场熵演化

研究了附加克尔（Ｋｅｒｒ）介质Ｊａｙｎｅｓ－Ｃｕｍｍｉｎｇｓ（Ｊ－Ｃ）模型场熵演化的动力学特性，讨论了克尔介质非线性相互作用以及失谐量对场熵演化的影响。     

An applicable and resource-economical scheme for the teleportation of W state via spin-path entangled quantum channel

In this paper, we accomplish the teleportation of an unknown three-particle maximally entangled W state by using a spin-path entangled quantum channel which may be realized experimentally based on the advanced theory and technique in Bose-Einstein condensate （BEC） of molecule, micro-fabricated wave guide and simple quantum logic gate. Similarly, we can make an arbitrary n-particle entangled Greenberger Horne-Zeilinger （GHZ） state （n ≥ 4） teleported through this kind of quantum channel. It may have important applications due to its resource-economic and practical features.     

Quantum speed limit time of a two-level atom under different quantum feedback control

We investigate the quantum speed limit time(QSLT) of a two-level atom under quantum-jump-based feedback control or homodyne-based feedback control. Our results show that the two different feedback control schemes have different influences on the evolutionary speed. By adjusting the feedback parameters, the quantum-jump-based feedback control can induce speedup of the atomic evolution from an excited state, but the homodyne-based feedback control cannot change the evolutionary speed. Additionally, the QSLT for the whole dynamical process is explored. Under the quantum-jump-based feedback control, the QSLT displays oscillatory behaviors, which implies multiple speed-up and speed-down processes during the evolution. While, the homodyne-based feedback control can accelerate the speed-up process and improve the uniform speed in the uniform evolution process.