Quantum network Bell nonlocality achieved with binary outcomes only

Erwan Don of the University of Geneva and colleagues have demonstrated quantum nonlocality within the simplest possible network configuration: a “triangle network” where three parties each make a single measurement. The researchers proved that quantum correlations defying classical explanation are achievable even when each measurement yields only one of two possible outcomes. This result establishes the smallest scenario supporting quantum nonlocality in networks, minimizing both the number of observed variables and their complexity. The work also introduces an efficient method for modeling quantum distributions in these networks, potentially accelerating future research in the field. Quantum nonlocality, a hallmark of quantum mechanics, has now been demonstrated within a remarkably simple network configuration, a triangle involving three parties each producing binary outputs. This finding directly refutes a prior conjecture suggesting binary outcomes were insufficient to establish Bell nonlocality in such a…