Local Unitary Equivalence of Multi-qubit Mixed Quantum States
Ming Li, Ting-Gui Zhang, Shao-Ming Fei, Xianqing Li-Jost,and Naihuan Jing
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Submission date: 19. Aug. 2014
published in: Physical review / A, 89 (2014) 6, art-no. 062325
DOI number (of the published article): 10.1103/PhysRevA.89.062325
PACS-Numbers: 03.67.-a, 02.20.Hj, 03.65.-w
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We present computable criterion for completely classifying multi-qubit quantum states under local unitary operations. The criterion can be used to detect whether two quantum states in multi-qubit systems are local unitary equivalent or not. Once obtaining the positive answer, we are further able to compute the corresponding unitary operators precisely. Since the scheme is based on the mean values of some quantum mechanical observables, it supplies an experimental way to judge the local equivalence of quantum states.