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论文类型：期刊论文

发表时间：2007-09-01

发表刊物：QUANTUM INFORMATION & COMPUTATION

收录刊物：SCIE

卷号：7

期号：7

页面范围：584-593

ISSN号：1533-7146

关键字：entanglement; tripartite entanglement; entanglement measure

摘要：In this paper, we present a new approach to study genuine tripartite entanglement existing in (2 x 2 x n)-dimensional quantum pure states. By utilizing the approach, we introduce a particular quantity to measure genuine tripartite entanglement. The quantity is shown to be an entanglement monotone in 2-dimensional subsystems (semi-monotone) and reaches zero for separable states and (2 x 2 x 2)-dimensional W states, hence is a good criterion to characterize genuine tripartite entanglement. Furthermore, the formulation for pure states can be conveniently extended to the case of mixed states by utilizing the kronecker product approximation technique. As applications, we give the analytic approximation for weakly mixed states, and study the genuine tripartite entanglement of two given weakly mixed states.