Quantum discord for two-qubit systems

doi:10.1103/PhysRevA.77.042303

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	Quantum discord for two-qubit systems
	Luo, Shunlong
	2008-04-01
发表期刊	PHYSICAL REVIEW A
ISSN	1050-2947
卷号	77 期号:4 页码:6
摘要	Quantum discord, as introduced by Olliver and Zurek [Phys. Rev. Lett. 88, 017901 (2001)], is a measure of the discrepancy between two natural yet different quantum analogs of the classical mutual information. This notion characterizes and quantifies quantumness of correlations in bipartite states from a measurement perspective, and is fundamentally different from the various entanglement measures in the entanglement vs separability paradigm. The phenomenon of nonzero quantum discord is a manifestation of quantum correlations due to noncommutativity rather than due to entanglement, and has interesting and significant applications in revealing the advantage of certain quantum tasks. We will evaluate analytically the quantum discord for a large family of two-qubit states, and make a comparative study of the relationships between classical and quantum correlations in terms of the quantum discord. We furthermore compare the quantum discord with the entanglement of formation, and illustrate that the latter may be larger than the former, although for separable states, the entanglement of formation always vanishes and thus is less than the quantum discord.
DOI	10.1103/PhysRevA.77.042303
语种	英语
WOS研究方向	Optics ; Physics
WOS类目	Optics ; Physics, Atomic, Molecular & Chemical
WOS记录号	WOS:000255457100040
出版者	AMER PHYSICAL SOC
引用统计
文献类型	期刊论文
条目标识符	http://ir.amss.ac.cn/handle/2S8OKBNM/6293
专题	应用数学研究所
通讯作者	Luo, Shunlong
作者单位	Chinese Acad Sci, Acad Math & Syst Sci, Beijing 100080, Peoples R China
推荐引用方式 GB/T 7714	Luo, Shunlong. Quantum discord for two-qubit systems[J]. PHYSICAL REVIEW A,2008,77(4):6.
APA	Luo, Shunlong.(2008).Quantum discord for two-qubit systems.PHYSICAL REVIEW A,77(4),6.
MLA	Luo, Shunlong."Quantum discord for two-qubit systems".PHYSICAL REVIEW A 77.4(2008):6.