2,251 research outputs found
The roles of quantum correlations in quantum cloning
In this paper, we study the entanglement and quantum discord of the output
modes in the unified state-dependent cloning and probabilistic
quantum cloning. The tripartite entanglement among the output modes and the
quantum cloning machine is also considered. We find that the roles of the
quantum correlations including the bipartite and tripartite entanglement and
quantum discord strongly depend on the quantum cloning machines as well as the
cloned state. In particular, it is found that this quantum cloning scheme can
be realizable even without any quantum correlation.Comment: Accepted by Eur. Phys. J.
Non-classicalities via perturbing local unitary operations
We study the nonclassical correlations in a two-qubit state by the perturbing
local unitary operation method. We find that the definitions of various
non-classicalities including quantum discord (QD), measurement-induced
nonlocality (MIN) and so on usually do not have a unique definition when
expressed as the perturbation of local unitary operations, so a given
non-classicality can lead to different definitions of its dual
non-classicality. In addition, it is shown that QD and MIN are not the
corresponding dual expressions in a simple set of unitary operations, even
though they are in their original definitions. In addition, we also consider
the non-classicalities in general dimensional systems
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