1207.1298 (Tiago Debarba et al.)

Witnessed entanglement and the geometric measure of quantum discord    [PDF]

Tiago Debarba, Thiago O. Maciel, Reinaldo O. Vianna

We establish interesting 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 has been conjectured before [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 for Werner states and for families of bound entangled states.

View original: http://arxiv.org/abs/1207.1298