Bell's theorem for temporal order

Funding

We thank G. Chiribella, G. Milburn, H. Wiseman and M. Vojinovic for feedback. M.Z. and F.C. acknowledge support through the Australian Research Council (ARC) Centre of Excellence for Engineered Quantum Systems (CE 110001013), Discovery Early Career Researcher Awards DE180101443, DE170100712 and the Templeton World Charity Foundation (TWCF 0064/AB38). I.P. acknowledges support of the NSF through a grant to ITAMP and the Branco Weiss Fellowship-Society in Science, administered by the ETH Zurich. C.B. acknowledges the support of the Austrian Science Fund (FWF) through the Doctoral Programme CoQuS, the project I-2526-N27 and I-2906, the research platform TURIS and the OAW Innovationsfond "Quantum Regime of Gravitational Source Masses". This publication was made possible through the support of a grant from the John Templeton Foundation and from the Foundational Questions Institute (FQXi) Fund. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. F.C. and M.Z. acknowledge the traditional owners of the land on which the University of Queensland is situated, the Turrbal and Jagera people.