title: Many-Body Localization Implies that Eigenvectors are Matrix-Product States.
abstract: The phenomenon of many-body localization has received a lot of attention recently, both for its implications in condensed-matter physics of allowing systems to be an insulator even at nonzero temperature as well as in the context of the foundations of quantum statistical mechanics, providing examples of systems showing the absence of thermalization following out-of-equilibrium dynamics. In this work, we establish a novel link between dynamical properties--a vanishing group velocity and the absence of transport--with entanglement properties of individual eigenvectors. For systems with a generic spectrum, we prove that strong dynamical localization implies that all of its many-body eigenvectors have clustering correlations. The same is true for parts of the spectrum, thus allowing for the existence of a mobility edge above which transport is possible. In one dimension these results directly imply an entanglement area law; hence, the eigenvectors can be efficiently approximated by matrix-product states.
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Friesdorf
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: A H
authors.initials: AH
authors.lastname: Werner
authors.affiliation: Computer Science Department, University College London, London WC1E 6BT, United Kingdom.
authors.forename: W
authors.initials: W
authors.lastname: Brown
authors.affiliation: Institute for Theoretical Physics, ETH Zurich, Wolfgang-Pauli-Strasse 27, 8093 Zurich, Switzerland.
authors.forename: V B
authors.initials: VB
authors.lastname: Scholz
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, 14195 Berlin, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Eisert