Eficiência de detecção em violações quânticas de bounds causais

Abstract

The distinction between cause and effect represents a significant challenge in physics, especially when dealing with correlated events. In quantum mechanics, this complexity is further accentuated due to phenomena such as superposition and quantum entanglement, which result in ”instantaneous”correlations between distant systems, known as quantum non-locality. This work investigates the detection efficiency in quantum violations of causal limits, which are inequalities that must be respected by any local classical theory. Determining the minimum conditions necessary for detection efficiency to allow the observation of these violations is essential from a physical standpoint, being a determining factor for understanding quantum causality. Using theoretical models, we identify the critical detection efficiency parameters for different measurement configurations. Additionally, we apply instrumental variables to generate causal inequalities and determine the minimum efficiencies necessary for the violation of these inequalities