Gühne Otfried, Tóth Géza, Hyllus Philipp, Briegel Hans J
Institut für Quantenoptik und Quanteninformation, Osterreichische Akademie der Wissenschaften, A-6020 Innsbruck, Austria.
Phys Rev Lett. 2005 Sep 16;95(12):120405. doi: 10.1103/PhysRevLett.95.120405. Epub 2005 Sep 14.
We investigate the nonlocal properties of graph states. To this aim, we derive a family of Bell inequalities which require three measurement settings for each party and are maximally violated by graph states. In turn, for each graph state there is an inequality maximally violated only by that state. We show that for certain types of graph states the violation of these inequalities increases exponentially with the number of qubits. We also discuss connections to other entanglement properties such as the positivity of the partial transpose or the geometric measure of entanglement.