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1.
Stability of trapped Bose-Einstein condensates in one-dimensional tilted optical lattice potential 下载免费PDF全文
Using the direct perturbation technique,this paper obtains a general perturbed solution of the Bose-Einstein condensates trapped in one-dimensional tilted optical lattice potential. We also gave out two necessary and sufficient conditions for boundedness of the perturbed solution. Theoretical analytical results and the corresponding numerical results show that the perturbed solution of the Bose-Einstein condensate system is unbounded in general and indicate that the Bose-Einstein condensates are Lyapunov-unstable. However,when the conditions for boundedness of the perturbed solution are satisfied,then the Bose-Einstein condensates are Lyapunov-stable. 相似文献
2.
Sudden death and revival of entanglement of two qubits coupled collectively to a thermal reservoir 下载免费PDF全文
In this paper, we investigate the entanglement of two qubits coupled collectively to a common thermal environment and find that the the collective decay can lead to a revival of the entanglement that has already been destroyed. We also show that the ability of the system to revival entanglement relies on the mean photon number of the thermal environment and the degree of entanglement of the initial state. 相似文献
3.
与运动原子相互作用的场的压缩效应 总被引:1,自引:1,他引:0
采用量子光学中时间演化算符方法,研究了与运动原子相互作用的场的压缩效应,揭示了光场的初始平均光子数和场模结构参数对光场压缩特性的影响,结果表明:适当选择系统参数,可获得在时间上持续压缩的压缩光。 相似文献
4.
与量子光场相互作用的运动原子的熵压缩 总被引:9,自引:1,他引:8
运用量子信息熵理论,研究了与量子光场相互作用的二能级运动原子的熵压缩,讨论了原子运动和场模结构对原子熵压缩的影响,并且比较了分别从基于信息熵测不准关系和海森伯测不准关系出发得出的结果,表明原子的运动导致了原子熵压缩的周期性演化;随着场模结构参量的增大,熵压缩的演化周期缩短,压缩时间延长;选择适当的系统参量,运动原子能够呈现长时间的持续熵压缩效应。当原子反转为零时,基于海伯堡测不准关系的方差压缩定义不再有效,而熵压缩实现了对原子压缩效应的高灵敏量度。 相似文献
5.
6.
We study three-body entanglement induced by spontaneous
emission in a three two-level atoms system by using the entanglement
tensor approach. The results show that the amount of entanglement
is strongly dependent on the initial state of the system and the species
of atoms. The three-body entanglement is the result of the coherent
superposition of the two-body entanglements. The larger the
two-body entanglement is, the stronger the three-body entanglement
is. On the other hand, if there exists a great difference in three two-body entanglement measures,
the three-body entanglement is very weak.
We also find that the maximum of the two-body entanglement
obtained with nonidentical atoms is greater than that obtained
with identical atoms via adjusting the difference in atomic frequency. 相似文献
7.
An effective teleportation scheme for an unknown ionic internal state via trapped ions is proposed without joint Bell-state measurement (BSM). In the constructed quantum channel process, we make use of entanglement swapping to avoid decrease in entanglement during the distributing of particles. Thus our scheme provides new prospects for quantum teleportatlon in a longer distance. The distinct advant.age of our scheme is insensitive to the heating of vibrational mode. Furthermore, our scheme has no any individual optical access, and the successful probability also can reach 1. 相似文献
8.
Teleportation for an Ionic Entangled Internal State by Entanglement Swapping 总被引:4,自引:0,他引:4 下载免费PDF全文
We present an effective scheme to teleport an unknown ionic entangled internal state via trapped ions without joint Bell-state measurement. In the constructed quantum channel process, we adopt entanglement swapping to avoid decrease of entanglement during the distribution of particles. Thus our scheme provides new prospects for quantum teleportation over longer distance. The distinct advantages of our scheme are that our scheme is insensitive to heating of vibrational mode and can be generalized to teleport an N-ion electronic entangled GHZ class state. Furthermore, in our scheme the success probability can reach 1. 相似文献
9.
Scheme for implementing quantum dense coding with four-particle decoherence-free states in an ion trap 下载免费PDF全文
This paper proposes an experimentally feasible scheme for implementing quantum dense coding of trapped-ion system in decoherence-free states. As the phase changes due to time evolution of components with different eigenenergies of quantum superposition are completely frozen, quantum dense coding based on this model would be perfect. The scheme is insensitive to heating of vibrational mode and Bell states can be exactly distinguished via detecting the ionic state. 相似文献
10.