共查询到20条相似文献,搜索用时 15 毫秒
1.
FAN Hong-Yi LIANG Xian-Ting 《理论物理通讯》2005,44(5):833-836
A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states. 相似文献
2.
FAN Hong-Yi LIANG Xian-Ting 《理论物理通讯》2005,44(11)
A quantum teleportation scheme to teleport a kind of tripartite entangled states of continuous variables by using a quantum channel composed of three bipartite entangled states is proposed. The joint Bell measurement is feasible because the bipartite entangled states are complete and the squeezed state has a natural representation in the entangled state basis. The calculation is greatly simplified by using the Schmidt decomposition of the entangled states. 相似文献
3.
In this paper, a protocol for quantum millionaire problem with continuous variables is proposed. In the protocol, two participants can compare the values of their fortune with the assistance of a semi-trusted third party (STTP). Only EPR states are exploited in our protocol while most other protocols exploited d-dimensional Bell states. Two participants are just required to perform single particle operations, which makes our protocol more efficiently. Our protocol can ensure fairness, correctness, security and high efficiency as well. In our protocol, only the two participants can deduce the results of comparisons, others include STTP will learn no information. Our protocol can resist various kinds of attacks from both the outside eavesdroppers and the inside participants, even the STTP. 相似文献
4.
Daniel Lehmann 《International Journal of Theoretical Physics》2009,48(1):261-281
Similarity-Projection structures abstract the numerical properties of real scalar product of rays and projections in Hilbert
spaces to provide a more general framework for Quantum Physics. They are characterized by properties that possess direct physical
meaning. They provide a formal framework that subsumes both classical Boolean logic concerned with sets and subsets and quantum
logic concerned with Hilbert space, closed subspaces and projections. They shed light on the role of the phase factors that
are central to Quantum Physics. The generalization of the notion of a self-adjoint operator to SP-structures provides a novel
notion that is free of linear algebra.
This work was partially supported by the Jean and Helene Alfassa fund for research in Artificial Intelligence. 相似文献
5.
David T. Pegg 《Foundations of Physics》2008,38(7):648-658
A retrocausal interpretation of quantum mechanics is examined and is applied to the problem of measuring an optical qubit
before the qubit is actually created. Although the predictions of the retrocausal interpretation are the same as for the conventional
causal picture, it provides a new perspective which should give a useful way of understanding some quantum mechanical processes. 相似文献
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采用连续变量量子密钥分发的纠缠模型,在反向协商情况下,研究法拉第镜不完善对系统安全密钥速率的影响.结果表明,不完善的法拉第镜会降低系统实际的密钥速率,并且降低安全通信距离,且随着法拉第镜失偏角度的增大而增大.此外,使用大的调制方差,可以降低法拉第镜不完善对系统的影响. 相似文献
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针对物理实验结果表示中学生难以理解的不确定度概念,详细阐述了误差和不确定度的基本定义,对二者之间的区别和联系进行了具体分析,使测量结果不确定度表达在定义上更加有着清晰的物理意义。 相似文献
10.
W. B. Cardoso 《International Journal of Theoretical Physics》2008,47(4):977-982
In this paper we show how to teleport N-entangled states of N-QED-cavities without Bell-state measurements. The method has potential application in teleportation schemes requiring multipartite
entanglements. The success probability and fidelity of the teleportation are also considered. 相似文献
11.
We construct the inhomogeneous quantum groups with continuous parameters which leave the boson and fermion algebras of field
theory invariant. 相似文献
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13.
YUAN Hong-Chun QI Kai-Guo 《理论物理通讯》2005,44(2):269-273
We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators. 相似文献
14.
YUAN Hong-Chun QI Kai-Guo 《理论物理通讯》2005,44(8)
We mostly investigate two schemes. One is to teleport a multi-mode W-type entangled coherent state using a peculiar bipartite entangled state as the quantum channel different from other proposals. Based on our formalism,teleporting multi-mode coherent state or squeezed state is also possible. Another is that the tripartite entangled state is used as the quantum channel of controlled teleportation of an arbitrary and unknown continuous variable in the case of three participators. 相似文献
15.
Quantum teleportation is an interesting feature of quantum mechanics. Entanglement is used as a link between two remote locations to transfer a quantum state without physically sending it – a process that cannot be realized utilizing merely classical tools. Furthermore it has become evident that teleportation is also an important element of future quantum networks and it can be an ingredient for quantum computation. This article reports for the first time the teleportation from light to atoms. In the experiment discussed, the quantum state of a light beam is transferred to an atomic ensemble. The key element of light‐atom entanglement created via a dispersive interaction lays the foundation for the protocol. 相似文献
16.
Supriya Mukherjee A. Ghose Choudhury A. Roy Chowdhury 《International Journal of Theoretical Physics》2006,45(4):820-834
We investigate the relation between the local variables of a discrete integrable lattice system and the corresponding separation variables, derived from the associated spectral curve. In particular, we have shown how the inverse transformation from the separation variables to the discrete lattice variables may be factorized as a sequence of canonical transformations. 相似文献
17.
No Heading The interplay between the tracial property and minimality of dispersions of states on projections of von Neumann algebras and C*-algebras is investigated. Let be a state on a C*-algebra A with the projection structure P(A). The dispersion () is defined as () = sup{(p) – (p)2 | p P(A)}. It is proved that () 2/9 whenever is a state on a real rank zero C*-algebra with no nonzero abelian representation. New characterization of traces in terms of dispersions is proved: A state on a von Neumann algebra without abelian and Type I2 direct summands is a trace if and only if has the minimal dispersion on all 3x3 matrix substructures. A similar characterization of semifinite normal traces on von Neumann algebras is obtained. The connection between unitary invariance of states and minimal dispersion property on C*-algebras is studied. Besides providing a new characterization of trace in terms of physically relevant properties, the existing results on hidden variables in W*- and C*-formalism of quantum mechanics are strengthen. 相似文献
18.
We construct, for any finite dimension n, a new hidden measurement model for quantum mechanics based on representing quantum transition probabilities by the volume of regions in projective Hilbert space. For n=2 our model is equivalent to the Aerts sphere model and serves as a generalization of it for dimensions n . 3 We also show how to construct a hidden variables scheme based on hidden measurements and we discuss how joint distributions arise in our hidden variables scheme and their relationship with the results of Fine [J. Math. Phys. 23 1306 (1982)]. 相似文献
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We explore the entanglement-related features exhibited by the dynamics of a composite quantum system consisting of a particle and an apparatus (here referred to as the “pointer”) that measures the position of the particle. We consider measurements of finite duration, and also the limit case of instantaneous measurements. We investigate the time evolution of the quantum entanglement between the particle and the pointer, with special emphasis on the final entanglement associated with the limit case of an impulsive interaction. We consider entanglement indicators based on the expectation values of an appropriate family of observables, and also an entanglement measure computed on particular exact analytical solutions of the particle–pointer Schrödinger equation. The general behavior exhibited by the entanglement indicators is consistent with that shown by the entanglement measure evaluated on particular analytical solutions of the Schrödinger equation. In the limit of instantaneous measurements the system’s entanglement dynamics corresponds to that of an ideal quantum measurement process. On the contrary, we show that the entanglement evolution corresponding to measurements of finite duration departs in important ways from the behavior associated with ideal measurements. In particular, highly localized initial states of the particle lead to highly entangled final states of the particle–pointer system. This indicates that the above mentioned initial states, in spite of having an arbitrarily small position uncertainty, are not left unchanged by a finite-duration position measurement process. 相似文献