共查询到20条相似文献,搜索用时 312 毫秒
1.
MA Zhi-Hao 《理论物理通讯》2008,50(5):1069-1070
Metric of quantum states plays an
important role in quantum information theory. In this letter, we find
the deep connection between quantum logic theory and quantum
information theory. Using the method of quantum logic, we can get a
famous inequality in quantum information theory, and we answer a
question raised by S. Gudder. 相似文献
2.
量子Fisher信息作为经典Fisher信息的自然推广,与量子信息中的纠缠判断具有密切联系.在表现为典型量子混沌特征的受击两分量玻色-爱因斯坦凝聚系统中,研究了与经典相空间对应的纠缠和量子Fisher信息动力学性质. 结果表明,初次撞击后的系统量子态是纠缠的,与初态所处相空间中的混乱程度无关.而量子Fisher信息的动力学演化对系统初态非常敏感,当初态处于混沌区域时,量子Fisher信息值比初态处于规则区域时大.利用这种较好的量子-经典对应关系,得到量子Fisher信息可以刻画量子混沌的结论.
关键词:
量子Fisher信息
玻色-爱因斯坦凝聚
量子混沌
量子-经典对应 相似文献
3.
A parametric quantum mechanical wavefunction naturally induces parametric probability distributions by taking absolute square, and we can consider its classical Fisher information. On the other hand, it also induces parametric rank-one projections which may be viewed as density operators, and we can talk about its quantum Fisher information. Among many versions of quantum Fisher information, there are two prominent ones. The first, defined via a quantum score function, was introduced by Helstrom in 1967 and is well known. The second, defined via the square root of the density operator, has its origin in the skew information introduced by Wigner and Yanase in 1963 and remains relatively unnoticed. This study is devoted to investigating the relationships between the classical Fisher information and these two versions of quantum Fisher information for wavefunctions. It is shown that the two versions of quantum Fisher information differ by a factor 2 and that they dominate the classical Fisher information. The non-coincidence of these two versions of quantum Fisher information may be interpreted as a manifestation of quantum discord. We further calculate the difference between the Helstrom quantum Fisher information and the classical Fisher information, and show that it is precisely the instantaneous phase fluctuation of the wavefunctions. 相似文献
4.
Quantum teleportation is one of the most important subjects in quantum information science. This is because quantum teleportation can be regarded as not only quantum information transfer but also a building block for universal quantum information processing. Furthermore, deterministic quantum information processing is very important for efficient processing and it can be realized with continuous-variable quantum information processing. In this review, quantum teleportation for continuous variables and related quantum information processing are reviewed from these points of view. 相似文献
5.
Dong Dao-yi Chen Zong-hai Zhang Chen-bin Chen Chun-lin 《Frontiers of Physics in China》2006,1(3):256-262
Feedback is a significant strategy for the control of quantum system. Information acquisition is the greatest difficulty in
quantum feedback applications. After discussing several basic methods for information acquisition, we review three kinds of
quantum feedback control strategies: quantum feedback control with measurement, coherent quantum feedback, and quantum feedback
control based on cloning and recognition. The first feedback strategy can effectively acquire information, but it destroys
the coherence in feedback loop. On the contrary, coherent quantum feedback does not destroy the coherence, but the capability
of information acquisition is limited. However, the third feedback scheme gives a compromise between information acquisition
and measurement disturbance. 相似文献
6.
大规模量子通信网络中,采用量子分组传输技术能有效提升发送节点的吞吐量,提高网络中链路的利用率,增强通信的抗干扰性能.然而量子分组的快速传输与路由器性能息息相关.路由器性能瓶颈将严重影响网络的可扩展性和链路的传输效率.本文提出一种量子通信网络分层结构,并根据量子密集编码和量子隐形传态理论,给出一种基于分层的量子分组信息传输方案,实现端到端的量子信息传输.该方案先将量子分组按照目的地址进行聚类,再按聚类后的地址进行传输.仿真结果表明,基于分层的量子分组信息传输方案能够有效减少量子分组信息在量子通信网络中的传输时间,并且所减少的时间与量子路由器性能与发送的量子分组数量有关.因此,本文提出的量子分组信息传输方案适用于大规模量子通信网络的构建. 相似文献
7.
《Physics letters. A》2020,384(28):126739
I introduce an algorithm to detect one-way quantum information between two interacting quantum systems, i.e. the direction and orientation of the information transfer in arbitrary quantum dynamics. I then build an information-theoretic quantifier of one-way information which satisfies a set of desirable axioms. In particular, it correctly evaluates whether correlation implies one-way quantum information, and when the latter is transferred between uncorrelated systems. In the classical scenario, the quantity measures information transfer between random variables. I also generalize the method to identify and rank concurrent sources of quantum information flow in many-body dynamics, enabling to reconstruct causal patterns in complex networks. 相似文献
8.
本文针对Kerr相互作用下系统中量子相干性的动力学分布进行了研究.所讨论系统包含两个没有相互作用的原子,每个原子都被囚禁在各自的光腔中,同时光腔被充满了非线性Kerr介质.研究发现非线性Kerr相互作用能够增加两原子间的量子相干性,而且增大的幅度会随着Kerr相互作用强度的增加而得以提高.其次,借助迹距离的方法,还探讨了非线性Kerr相互作用对于原子与光腔之间的量子信息流动的影响,发现Kerr相互作用可以加快量子信息回流到原子子系统中,抑制原子子系统与其余子系统间的量子信息交换,阻碍量子信息在系统中不同子系统间的流动,从而保护原子子系统中拥有的量子信息. 相似文献
9.
CAI Qing-yu LI Bai-wen 《原子与分子物理学报》2004,21(Z1):380-382
We analyze the connection between quantum operations and accessible information. And we find that the accessible information decreases under quantum operations. We show that it is impossible to perfectly manipulate an unknown state in an open quantum system. That the accessible information decreases under quantum operations gives a fundamental limitation in the microscopic world. 相似文献
10.
Farzam Nosraty 《理论物理通讯》2016,65(2):225-230
In the present study, time evolution of quantum Cramer–Rao bound of entangled N00N state, as phase sensitivity, is determined by the aid of quantum estimation theory in the presence decoherence channels. Also, the dynamic quantum process as decoherence approach is characterized by quantum fisher information flow and entanglement amount in order to distinguish between Markovian and Non-Markovian process. The comparison between quantum fisher information and quantum fisher information flow assists to comprehend the phase sensitivity evolution corresponding to Non-Markovian and Markovian process. Furthermore, as result of backflow of information from the environment to system, the phase sensitivity corresponding memory effect of environment are revived after complete decay and increase in the few times. 相似文献
11.
12.
Maroufi B. Laghmach R. EL Hadfi H. Daoud M. 《International Journal of Theoretical Physics》2021,60(8):3103-3114
The quantum Fisher information defined via the symmetric logarithmic derivative and the skew information are two different aspects describing the information contents of quantum mechanical density operators. They are considered as natural generalizations of the classical Fisher information and constitute key ingredients in the emerging field of quantum metrology. In this paper, we give the analytical expression of quantum Fisher information and skew information for two-qubit system prepared in a two-qubit state of X type.
相似文献13.
ZHANG Yun 《Frontiers of Physics》2008,3(2):126
Quantum information and quantum optics are rapidly advancing areas of modern physics. As an important device in quantum optics and quantum information, the optical parametric amplifier/oscillator (OPA/O) has been extensively studied and applied to the generation of non-classical state since the 1980s. This article reviews the progress in the generation of non-classical state from an OPO/A and application of twin beams in quantum optics and quantum information. 相似文献
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16.
We investigate quantum Fisher information dynamics in two component Bose-Einstein condensate interacting spins with an external field. Approximate analytical expressions of quantum Fisher information is presented. Our analysis shows that quantum Fisher information is controlled by adjusting the strength of the external field and the total atomic number. It is shown that the maximal mean quantum Fisher information is occurred and the phase estimation is enhanced to the Heisenberg limit under some conditions. 相似文献
17.
Yun Zhang 《Frontiers of Physics in China》2008,3(2):126-152
Quantum information and quantum optics are rapidly advancing areas of modern physics. As an important device in quantum optics
and quantum information, the optical parametric amplifier/oscillator (OPA/O) has been extensively studied and applied to the
generation of non-classical state since the 1980s. This article reviews the progress in the generation of non-classical state
from an OPO/A and application of twin beams in quantum optics and quantum information
相似文献
18.
利用全量子理论和数值计算方法,研究隧穿量子点分子模型与光场相互作用的量子信息保真度,通过计算机模拟出量子点分子、光场和系统的保真度随时间的演化图像,分析了压缩系数和失谐量对量子信息保真度的影响.结果表明:改变初始光场的压缩系数和失谐量能调节相互作用系统的量子信息保真度. 相似文献
19.
Tian-Yu Ye 《International Journal of Theoretical Physics》2014,53(11):3719-3727
At present, a lot of quantum dialogue protocols have the problem of information leakage, especially the ones merely using a single quantum state as the quantum resource. In this paper, the author successfully puts forward a novel kind of information leakage resistant quantum dialogue protocol merely using a single quantum entangled state. This kind of quantum dialogue protocol uses the measurement correlation property of a single quantum entangled state to prevent the information leakage problem. Its Bell state version is illustrated in detail at first in this paper, then it is generalized to the cases of three-particle, four-particle and five-particle quantum entangled states. Different from those previous information leakage resistant quantum dialogue protocols, the proposed protocol needs neither the auxiliary quantum state nor the entanglement swapping technology of quantum state. 相似文献