2020/02/24 by Zhang, Tian, Dahlsten, Oscar, Vedral, Vlatko
#FOS: Physical sciences #High Energy Physics - Theory (hep-th) #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2002.10448
We investigate quantum correlations in time in different approaches. We assume that temporal correlations should be treated in an even-handed manner with spatial correlations. We compare the pseudo-density matrix formalism with several other approaches: indefinite causal structures, consistent histories, generalised quantum games, out-of-time-order correlations(OTOCs), and path integrals. We establish close relationships among these space-time approaches in non-relativistic quantum theory, resulting in a unified picture. With the exception of amplitude-weighted correlations in the path integral formalism, in a given experiment, temporal correlations in the different approaches are the same or operationally equivalent.