Lower bound of concurrence for qubit systems
نویسندگان
چکیده
منابع مشابه
Lower bound of concurrence for qubit systems
We study the concurrence of four-qubit quantum states and provide analytical lower bounds of concurrence in terms of the monogamy inequality of concurrence for qubit systems. It is shown that these lower bounds are able to improve the existing bounds and detect entanglement better. The approach is generalized to arbitrary qubit systems.
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By focusing on the X-matrix part of a density matrix of two qubits we provide an algebraic lower bound for the concurrence. The lower bound is generalized for cases beyond two qubits and can serve as a sufficient condition for non-separability for bipartite density matrices of arbitrary dimension. Experimentally, our lower bound can be used to confirm non-separability without performing a compl...
متن کاملLower bound of multipartite concurrence based on sub-partite quantum systems
We study the concurrence of arbitrary dimensional multipartite quantum systems. An explicit analytical lower bound of concurrence for four-partite mixed states is obtained in terms of the concurrences of tripartite mixed states. Detailed examples are given to show that our lower bounds improve the existing lower bounds of concurrence. The approach is generalized to five-partite quantum systems.
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ژورنال
عنوان ژورنال: Quantum Information Processing
سال: 2013
ISSN: 1570-0755,1573-1332
DOI: 10.1007/s11128-013-0693-7