Superdensity operators for spacetime quantum mechanics

Jordan Cotler, Chao Ming Jian, Xiao Liang Qi, Frank Wilczek

    Research output: Contribution to journalArticlepeer-review

    33 Scopus citations


    We introduce superdensity operators as a tool for analyzing quantum information in spacetime. Superdensity operators encode spacetime correlation functions in an operator framework, and support a natural generalization of Hilbert space techniques and Dirac’s transformation theory as traditionally applied to standard density operators. Superdensity operators can be measured experimentally, but accessing their full content requires novel procedures. We demonstrate these statements on several examples. The superdensity formalism suggests useful definitions of spacetime entropies and spacetime quantum channels. For example, we show that the von Neumann entropy of a super-density operator is related to a quantum generalization of the Kolmogorov-Sinai entropy, and compute this for a many-body system. We also suggest experimental protocols for measuring spacetime entropies.

    Original languageEnglish (US)
    Article number93
    JournalJournal of High Energy Physics
    Issue number9
    StatePublished - Sep 1 2018


    • Lattice Quantum Field Theory
    • Space-Time Symmetries

    ASJC Scopus subject areas

    • Nuclear and High Energy Physics


    Dive into the research topics of 'Superdensity operators for spacetime quantum mechanics'. Together they form a unique fingerprint.

    Cite this