Quantum observation scheme universally identifying causalities from correlations
arXiv:1903.03449 · doi:10.1103/PhysRevA.101.062103
Abstract
It has long been recognized as a difficult problem to determine whether the observed statistical correlation between two classical variables arise from causality or from common causes. Recent research has shown that in quantum theoretical framework, the mechanisms of entanglement and quantum coherence provide an advantage in tackling this problem. In some particular cases, quantum common causes and quantum causality can be effectively distinguished using observations only. However, these solutions do not apply to all cases. There still exist enormous cases in which quantum common causes and quantum causality can not be distinguished. In this paper, along the line of considering unitary transformation as causality in the quantum world, we formally show quantum common causes and quantum causality are universally separable. Based on the analysis, we further provide a general method to discriminate the two.
References in corpus (18)
- Quantum Non-Markovianity: Characterization, Quantification and Detection
- Measure for the Non-Markovianity of Quantum Processes
- Probabilistic theories with purification
- The lesson of causal discovery algorithms for quantum correlations: Causal explanations of Bell-inequality violations require fine-tuning
- Quantum causal modelling
- Perfect discrimination of no-signalling channels via quantum superposition of causal structures
- Quantum common causes and quantum causal models
- Theory-independent limits on correlations from generalised Bayesian networks
- Inferring causal structure: a quantum advantage
- Quantum Dynamics as an analog of Conditional Probability
- Beyond Bell's Theorem II: Scenarios with arbitrary causal structure
- Quantum Bayesian Nets
- A graph-separation theorem for quantum causal models
- New Slant on the EPR-Bell Experiment
- A quantum causal discovery algorithm
- Identification of a reversible quantum gate: assessing the resources
- Two-qubit causal structures and the geometry of positive qubit-maps
- Discrimination Between Quantum Common Causes and Quantum Causality