Entanglement and discord of the superposition of Greenberger-Horne-Zeilinger states

被引:32
作者
Parashar, Preeti [1 ]
Rana, Swapan [1 ]
机构
[1] Indian Stat Inst, Phys & Appl Math Unit, Kolkata, India
来源
PHYSICAL REVIEW A | 2011年 / 83卷 / 03期
关键词
RELATIVE ENTROPY;
D O I
10.1103/PhysRevA.83.032301
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
We calculate the analytic expression for geometric measure of entanglement for arbitrary superposition of two N-qubit canonical orthonormal Greenberger-Horne-Zeilinger (GHZ) states and the same for two W states. In the course of characterizing all kinds of nonclassical correlations, an explicit formula for quantum discord (via relative entropy) for the former class of states has been presented. Contrary to the GHZ state, the closest separable state to the W state is not classical. Therefore, in this case, the discord is different from the relative entropy of entanglement. We conjecture that the discord for the N-qubit W state is log(2) N.
引用
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页数:7
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共 40 条
[11]   Entanglement of multiparty-stabilizer, symmetric, and antisymmetric states [J].
Graduate School of Information Sciences, Tohoku University, Aoba-ku, Sendai 980-8579, Japan ;
不详 ;
不详 ;
不详 ;
不详 ;
不详 ;
不详 ;
不详 .
Physical Review A - Atomic, Molecular, and Optical Physics, 2008, 77 (01)
[12]   Quantum entanglement [J].
Horodecki, Ryszard ;
Horodecki, Pawel ;
Horodecki, Michal ;
Horodecki, Karol .
REVIEWS OF MODERN PHYSICS, 2009, 81 (02) :865-942
[13]   Geometric measure of entanglement for symmetric states [J].
Huebener, Robert ;
Kleinmann, Matthias ;
Wei, Tzu-Chieh ;
Gonzalez-Guillen, Carlos ;
Guehne, Otfried .
PHYSICAL REVIEW A, 2009, 80 (03)
[14]   Analytical formula connecting entangled states and the closest disentangled state [J].
Ishizaka, S .
PHYSICAL REVIEW A, 2003, 67 (06) :4
[15]  
Jung E, 2008, QUANTUM INF COMPUT, V8, P925
[16]   Difficulties in analytic computation for relative entropy of entanglement [J].
Kim, Hungsoo ;
Hwang, Mi-Ra ;
Jung, Eylee ;
Park, DaeKil .
PHYSICAL REVIEW A, 2010, 81 (05)
[17]   Quantum Discord and the Geometry of Bell-Diagonal States [J].
Lang, Matthias D. ;
Caves, Carlton M. .
PHYSICAL REVIEW LETTERS, 2010, 105 (15)
[18]   Entanglement of superpositions [J].
Linden, Noah ;
Popescu, Sandu ;
Smolin, John A. .
PHYSICAL REVIEW LETTERS, 2006, 97 (10)
[19]   Geometric measure of quantum discord [J].
Luo, Shunlong ;
Fu, Shuangshuang .
PHYSICAL REVIEW A, 2010, 82 (03)
[20]   Multiqubit symmetric states with high geometric entanglement [J].
Martin, J. ;
Giraud, O. ;
Braun, P. A. ;
Braun, D. ;
Bastin, T. .
PHYSICAL REVIEW A, 2010, 81 (06)