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991.
CHEN Chang-Yong 《理论物理通讯》2008,49(5):1187-1190
We propose an etticient scheme for generating the macroscopic superpositions and the entanglement between the high-order squeezed vacuum states by considering the multi-photon interaction of N two-level atoms in a cavity with high quality factor, assisted by a strong driving field. Through specific choices of the cavity detuning, a number of multi-party entangled states between the atoms and the high-order squeezed vacuum states and among the high-order squeezed vacuum states of the cavities can be prepared, including also the macroscopic "Schrodinger cats" of the high- order squeezed vacuum states, the entangled states of the macroscopic "Schrodinger cats", and so on. Possible extension and application of our scheme are discussed. Our scheme is reachable within the current techniques in the cavity QED. 相似文献
992.
LIN Gong-Wei CHEN Li-Bo DU Qian-Hua LAN Jie-Qin LIN Xiu-Min 《理论物理通讯》2008,49(6):1483-1486
Based on the input-output relation of a one-sided cavity, we propose an experimental scheme to implement entanglement swapping with photons. In the ideal case, the successful probability of the scheme approaches unity. In addition, the protocol can be extended to establish multiphoton entanglement among distant users in a communication network. 相似文献
993.
We present a (t,n) threshold multiparty controlled quantum teleportation protocol of an arbitrary m-qubit quantum state between two remote parties. The unknown m-qubit quantum state can be recovered by the receiver under control of a subset of the n controllers if the number of the subset is larger than or equal to a threshold, say, t, but not for any t-1 or fewer controllers. Our scheme seems to be more practical and more flexible than otherexisting protocols. The quantum resource required is just mEinstein-Podolsky-Rosen (EPR) pairs plus some single photons. Thetechniques required are only Bell state measurement, single-qubitunitary operation and von Neumann measurement. So our scheme is alsofeasible with present-day technique. 相似文献
994.
A quantum secure direct communication scheme using dense coding is proposed. At first, the sender (Alice) prepares four-particle genuine entangled states and shares them with the receiver (Bob) by sending two particles in each entangled state to him. Secondly, Alice encodes secret information by performing the unitarytransformations on her particles and transmits them to Bob. Finally, Bob performs the joint measurements on his particles to decode the secret information. The two-step security test guarantees the security of communication. 相似文献
995.
In this paper, we study the entanglement dynamics of two-spin
Heisenberg XYZ model with the Dzialoshinskii--Moriya (DM)
interaction. The system is initially prepared in the Werner state.
The effects of purity of the initial state and DM coupling parameter
on the evolution of entanglement are investigated. The necessary and
sufficient condition for the appearance of the entanglement sudden
death (ESD) phenomenon has been deduced. The result shows that the
ESD always occurs if the initial state is sufficiently impure for
the given coupling parameter or the DM interaction is sufficiently
strong for the given initial state. Moreover, the critical values of
them are calculated. 相似文献
996.
Recently, it has been become known that a quantum entangled state plays an important role in fields of quantum information theory, such as quantum teleportation and quantum computation. Research on quantifying entangled states has been carried out using several measures. In this Letter, we will adopt this method using quantum mutual entropy to measure the degree of entanglement in the time development of the Jaynes–Cummings model. 相似文献
997.
聚合物熔体本构关系的研究进展 总被引:5,自引:1,他引:4
总结和评述了聚合物熔体本构关系的研究成果,并着重介绍分子链缠结动力学的结构网络本构理论. 相似文献
998.
In chaotic entanglement, pairs of interacting classically-chaotic systems are induced into a state of mutual stabilization that can be maintained without external controls and that exhibits several properties consistent with quantum entanglement. In such a state, the chaotic behavior of each system is stabilized onto one of the system’s many unstable periodic orbits (generally located densely on the associated attractor), and the ensuing periodicity of each system is sustained by the symbolic dynamics of its partner system, and vice versa. Notably, chaotic entanglement is an entropy-reversing event: the entropy of each member of an entangled pair decreases to zero when each system collapses onto a given period orbit. In this paper, we discuss the role that entropy plays in chaotic entanglement. We also describe the geometry that arises when pairs of entangled chaotic systems organize into coherent structures that range in complexity from simple tripartite lattices to more involved patterns. We conclude with a discussion of future research directions. 相似文献
999.
In this paper, we use certain norm inequalities to obtain new uncertain relations based on the Wigner-Yanase skew information. First for an arbitrary finite number of observables we derive an uncertainty relation outperforming previous lower bounds. We then propose new weighted uncertainty relations for two noncompatible observables. Two separable criteria via skew information are also obtained. 相似文献
1000.
We explore the existence of monogamy relations in terms of Rényi-α entanglement. By using the power of the Rényi-α entanglement, we establish a class of tight monogamy relations of multiqubit entanglement with larger lower bounds than the existing monogamy relations for α≥2, the power η1, and 2α≥(7~(1/2)-1)/2, the power η2, respectively. 相似文献