title: Genuine hidden quantum nonlocality.
abstract: The nonlocality of certain quantum states can be revealed by using local filters before performing a standard Bell test. This phenomenon, known as hidden nonlocality, has been so far demonstrated only for a restricted class of measurements, namely, projective measurements. Here, we prove the existence of genuine hidden nonlocality. Specifically, we present a class of two-qubit entangled states, for which we construct a local model for the most general local measurements, and show that the states violate a Bell inequality after local filtering. Hence, there exist entangled states, the nonlocality of which can be revealed only by using a sequence of measurements. Finally, we show that genuine hidden nonlocality can be maximal. There exist entangled states for which a sequence of measurements can lead to maximal violation of a Bell inequality, while the statistics of nonsequential measurements is always local.
authors.affiliation: Département de Physique Théorique, Université de Genève, 1211 Genève, Switzerland.
authors.forename: Flavien
authors.initials: F
authors.lastname: Hirsch
authors.forename: Marco Túlio
authors.initials: MT
authors.lastname: Quintino
authors.forename: Joseph
authors.initials: J
authors.lastname: Bowles
authors.forename: Nicolas
authors.initials: N
authors.lastname: Brunner