Entanglement, non-Markovianity, and causal non-separability

Simon Milz, Felix Pollock, Thao Phuong Le, Giulio Chiribella, Kavan Modi

Research output: Contribution to journalArticleResearchpeer-review

8 Citations (Scopus)


Quantum mechanics, in principle, allows for processes with indefinite causal order. However, most of these causal anomalies have not yet been detected experimentally. We show that every such process can be simulated experimentally by means of non-Markovian dynamics with a measurement on additional degrees of freedom. In detail, we provide an explicit construction to implement arbitrary a causal processes. Furthermore, we give necessary and sufficient conditions for open system dynamics with measurement to yield processes that respect causality locally, and find that tripartite entanglement and nonlocal unitary transformations are crucial requirements for the simulation of causally indefinite processes. These results show a direct connection between three counter-intuitive concepts: entanglement, non-Markovianity, and causal non-separability.

Original languageEnglish
Article number033033
Number of pages15
JournalNew Journal of Physics
Issue number3
Publication statusPublished - 1 Mar 2018


  • causally disordered processes
  • entanglement
  • non-Markovianity

Cite this