A graph-separation theorem for quantum causal models
A graph-separation theorem for quantum causal models
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DOI:
10.1088/1367-2630/17/7/073020
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发表时间:
2014-06
影响因子:
3.3
通讯作者:
J. Pienaar;Č. Brukner
中科院分区:
文献类型:
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作者:
J. Pienaar;Č. Brukner
A causal model is an abstract representation of a physical system as a directed acyclic graph (DAG), where the statistical dependencies are encoded using a graphical criterion called ‘d-separation’. Recent work by Wood and Spekkens shows that causal models cannot, in general, provide a faithful representation of quantum systems. Since d-separation encodes a form of Reichenbach’s common cause principle (RCCP), whose validity is questionable in quantum mechanics, we propose a generalized graph separation rule that does not assume the RCCP. We prove that the new rule faithfully captures the statistical dependencies between observables in a quantum network, encoded as a DAG, and reduces to d-separation in a classical limit.