Towards an equivalence between maximal entanglement and maximal quantum nonlocality

Towards an equivalence between maximal entanglement and maximal quantum nonlocality

Lipinska, V. (TU Delft QID/Wehner Group; TU Delft QuTech Advanced Research Centre; Barcelona Institute of Science and Technology (BIST))
Curchod, Florian J. (Barcelona Institute of Science and Technology (BIST))
Máttar, Alejandro (Barcelona Institute of Science and Technology (BIST))
Acín, Antonio (Barcelona Institute of Science and Technology (BIST); Catalan Institution for Research and Advanced Studies (ICREA))

2018-06-01

While all bipartite pure entangled states are known to generate correlations violating a Bell inequality, and are therefore nonlocal, the quantitative relation between pure state entanglement and nonlocality is poorly understood. In fact, some Bell inequalities are maximally violated by non-maximally entangled states and this phenomenon is also observed for other operational measures of nonlocality. In this work, we study a recently proposed measure of nonlocality defined as the probability that a pure state displays nonlocal correlations when subjected to random measurements. We first prove that this measure satisfies some natural properties for an operational measure of nonlocality. Then, we show that for pure states of two qubits the measure is monotonic with entanglement for all correlation two-outcome Bell inequalities: for all these inequalities, the more the state is entangled, the larger the probability to violate them when random measurements are performed. Finally, we extend our results to the multipartite setting.

entanglement
entanglement anomaly
nonlocal volume
nonlocality measure
quantum correlations
quantum nonlocality

http://resolver.tudelft.nl/uuid:a76edb73-f10f-4d07-8f79-643ec02dffad

https://doi.org/10.1088/1367-2630/aaca22

1367-2630

New Journal of Physics, 20 (6)

Institutional Repository

journal article

© 2018 V. Lipinska, Florian J. Curchod, Alejandro Máttar, Antonio Acín