Resilience of realism-based nonlocality to local disturbance

TL;DR

This paper studies the robustness of realism-based nonlocality, a form of quantum correlation, under local disturbances, showing it is highly persistent and more widespread than other quantum correlations.

Contribution

It introduces a monitoring procedure to analyze the resilience of realism-based nonlocality and demonstrates its robustness compared to other quantum correlations.

Findings

Realism-based nonlocality is the most persistent quantum correlation.

It forms a strict superset of other quantum states like discordant and entangled states.

It does not undergo sudden death under local monitoring.

Abstract

Employing a procedure called monitoring---via a completely positive trace-preserving map that is able to interpolate between weak and projective measurements---we investigate the resilience of the recently proposed realism-based nonlocality to local and bilocal weak measurements. This analysis indicates realism-based nonlocality as the most ubiquitous and persistent form of quantumness within a wide class of quantum-correlation quantifiers. In particular, we show that the set of states possessing this type of quantumness forms a strict superset of symmetrically discordant states and, therefore, of discordant, entangled, steerable, and Bell-nonlocal states. Moreover, we find that, under monitoring, realism-based nonlocality is not susceptible to sudden death.