Open AccessNegative quantum conditional entropy and the entanglement measure of a kind of mixed state of bipartite quantum system
Author(s) -
Zhou Bing-Ju,
Xiaojuan Liu,
Fang Mao-Fa,
Zhou Qing-Ping,
Mingwei Liu
Publication year - 2007
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.56.3937
Subject(s) - quantum discord , quantum entanglement , squashed entanglement , quantum mechanics , conditional entropy , physics , quantum relative entropy , joint quantum entropy , statistical physics , entanglement witness , quantum , mathematics , statistics , principle of maximum entropy
From negative quantum conditional entropy point of view this paper intestigates the entanglement measure of the prue state and a kind of mixed state of bipartite quantum system. Also this paper gives a definition of quantum conditional entropy of entanglement EAB(ρAB) and proves that it satisfies the four fundamental conditions of a entanglement measure for a kind of mixed state of 2×2 quantum system by this negative quantum conditional entropy Using conditional entropy of entanglement, this paper investigates the quantum entanglement between the two identical two-level atoms simultaneously interacting with vacuum cavity field as an application. This paper compares conditional entropy of entanglement and concurrence at the same condition, and the result shows that the curves of their evolvements are identical. These obtained results test and verifys that conditions of an entanglement measure may be taken as the entanglement measure of the prue state and a kind of mixed state of bipartite quantum system.