From nonlocality quantifiers for behaviors to nonlocality quantifiers for states

Abstract

We define an alternative way of quantifying nonlocality of states based on Bell nonlocality of behaviors, called the trace-weighted nonlocal volume. The construction is based on the nonlocal volume, a quantifier of nonlocality for states that counts the volume of the set of measurements that give rise to nonlocal behaviors when applied to this state, plus the trace distance, a quantifier of nonlocality for behaviors based on the distance between the behavior and the local set. The key difference from preceding candidates was the introduction of a quantifier of nonlocality to weight each contribution from behaviors in the nonlocal volume. We list some interesting properties of this quantifier and investigate the (2, 2, 2) and (2, 3, 2) scenarios. We show that the weak anomaly of nonlocality for the (2, 2, 3) scenario persists, but the local minimum for nonlocality with the trace-weighted nonlocal volume occurs in a different state as compared to the minimum for the nonweighted version, showing that the weak anomaly is not an intrinsic characteristic of the scenario, but is strongly dependent of the choice of quantifier.

Caracterizando e quantificando não-localidade de estados quânticos a partir de quantificadores para comportamentos e desigualdades de Bell

“…Vimos uma maneira alternativa de quantificar a não-localidade de estados com base na não-localidade de Bell de comportamentos [85]. A principal diferença de candidatos anteriores foi a introdução de um quantificador de não-localidade para ponderar cada contribuição de comportamentos no volume não-local.…”