Genuine Multiparty Quantum Correlations versus Bell Nonlocality

1 07/2016

Friday, 01 Jul. 2016, 15:00 - 16:00

Presenter: Avijit Misra
Host: Miguel Navascues
Where: IQOQI Seminar Room, 2nd Floor, Boltzmanngasse 3, 1090 Vienna

Computing genuine multiparty entanglement of an arbitrary quantum state is important yet not an easy task in general. The task is much more challenging for an arbitrary mixed state. Exploiting symmetries of certain classes of mixed states, we compute a genuine multiparty entanglement measure, the generalized geometric measure for the same. The chosen states have different ranks and consist of an arbitrary number of parties.
Apart from quantifying genuine multiparty quantum correlation of a quantum state, establishing its connection with nonlocal correlations is also significant from both fundamental and applied perspectives. Though these two concepts are intimately related, establishing the precise link is highly challenging for multipartite quantum states. We find a single parameter family of genuinely entangled three qubit pure states that exhibits maximum Bell inequality violation by the reduced bipartite systems for a fixed amount of genuine tripartite correlation. This in turn implies that there exists a complementary relation between the Bell inequality violation by the reduced bipartite systems and the genuine tripartite correlation present in the three qubit pure states. The tangle, generalized geometric measure and discord monogamy score have been considered to quantify the genuine quantum correlation of the three qubit pure states. This complementary relation suggests that the Bell inequality violation in the reduced two qubit system comes at the cost of the total tripartite correlation present in the entire system.
References: arXiv: 1509.02085; arXiv: 1512:01770.51