Quantum correlation swapping between Bell-diagonal states

Abstract Quantum correlation (QC) swapping is a generalization of quantum entanglement swapping, in which the concerned QCs can be quantum entanglement, QC beyond quantum entanglement, or both of them. In general, QC swapping is different from quantum entanglement swapping. Obviously, the study range of the former is beyond than the latter, and the former can give more interesting and significant applications in quantum information processings. So far, QC swapping has been studied explicitly only for a rather limited set of two-qubit quantum states as the initial states and cases for more general QC swapping with multi-parameter initial states are not known. In this article, we explore the QC swapping case with three-parameter Bell-diagonal (BD) states as the initial states. The familiar QC measure, quantum discord (Ollivier and Zurek 2001 Phys. Rev. Lett. 88 017901), is utilized to quantify all the QCs in the concerned states. It is found that a long-distance shared QC can be acquired through the BD-initial states case of QC swapping. Moreover, some distinct features and characteristics can be exposed.