Semi-device-independent certification of indefinite causal order

  title={Semi-device-independent certification of indefinite causal order},
  author={Jessica Bavaresco and Mateus Ara'ujo and {\vC}aslav Brukner and Marco T'ulio Quintino},
When transforming pairs of independent quantum operations according to the fundamental rules of quantum theory, an intriguing phenomenon emerges: some such higher-order operations may act on the input operations in an indefinite causal order. Recently, the formalism of process matrices has been developed to investigate these noncausal properties of higher-order operations. This formalism predicts, in principle, statistics that ensure indefinite causal order even in a device-independent scenario… 

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