Detecting Nonclassicality in Quantum Networks via a Novel Intervention FrameworkConfirmed

by Santiago Zamora (International Institute of Physics, Federal University of Rio Grande do Norte (IIP-UFRN))

Monday Feb 2, 2026, 11:00 AM → 12:30 PM America/Toronto

PI/3-301 - Alice Room (Perimeter Institute for Theoretical Physics)

Causal interventions have emerged as an effective tool for certifying nonclassicality, offering improved detection efficiency and robustness to noise compared to purely observational approaches. However, standard node interventions (Pearl interventions) become uninformative in space-like separated networks such as the Triangle Network.

 

To address this limitation, we introduce Latent Splitting, a framework that generalizes the notion of intervention from observable variables to the latent quantum sources themselves. Latent Splitting subsumes standard interventions as a special case and provides an effective causal probe for the Triangle Network. Using this framework, we derive robust witnesses for the RGB4 family and establish nonclassicality in the minimal binary-outcome triangle scenario, a regime previously thought to admit a classical model.