Robustness of multiqubit entanglement in the independent decoherence model

作     者：Somshubhro Bandyopadhyay Daniel A. Lidar 

作者机构：Chemical Physics Theory Group Chemistry Department and Center for Quantum Information and Quantum Control University of Toronto Toronto ON M5S 3H6 Canada Department of Chemistry and Department of Electrical Engineering-Systems University of Southern California Los Angeles CA 90089 USA 

出 版 物：《Physical Review A》 (物理学评论A辑：原子、分子和光学物理学)

年 卷 期：2005年第72卷第4期

页      面：042339-042339页

核心收录：

学科分类：070207[理学-光学] 07[理学] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

主　　题：NOISY CHANNELS STATES 

摘      要：We study the robustness of the Greenberger-Horne-Zeilinger (“cat) class of multipartite states under decoherence. The noise model is described by a general completely positive map for qubits independently coupled to the environment. In particular, the robustness of N-party entanglement is studied in the large N limit when (a) the number of spatially separated subsystems is fixed but the size of each subsystem becomes large and (b) the size of the subsystems is fixed while their number becomes arbitrarily large. We obtain conditions for entanglement in these two cases. Among our other results, we show that the parity of an entangled state (i.e., whether it contains an even or odd number of qubits) can lead to qualitatively different robustness of entanglement under certain conditions.