29 research outputs found
Role of Quantumness of Correlations in Entanglement Resource Theory
Quantum correlations: entanglement and quantumness of correlations are main
resource for quantum information theory. In this chapter it is presented the
scenarios which quantumness of correlations plays an interesting role in
entanglement distillation protocol. By means of Koashi - Winter relation, it is
discussed that quantumness of correlations are related to the irreversibility
of the entanglement distillation protocol. The activation protocol is
introduced, and it is proved that quantumness of correlations can create
distillable entanglement between the system and the measurement apparatus
during a local measurement process.Comment: Full chapter contribution of Advanced Technologies of Quantum Key
Distribution, ISBN 978-953-51-5289-
Witnessed entanglement and the geometric measure of quantum discord
We establish relations between geometric quantum discord and entanglement
quantifiers obtained by means of optimal witness operators. In particular, we
prove a relation between negativity and geometric discord in the
Hilbert-Schmidt norm, which is slightly different from a previous conjectured
one [Phys. Rev. A 84, 052110 (2011)].We also show that, redefining the
geometric discord with the trace norm, better bounds can be obtained. We
illustrate our results numerically.Comment: 8 pages + 3 figures. Revised version with erratum for PRA 86, 024302
(2012). Simplified proof that discord is bounded by entanglement in any nor