title: Pushing the limits of the eigenstate thermalization hypothesis towards mesoscopic quantum systems.
abstract: In the ongoing discussion on thermalization in closed quantum many-body systems, the eigenstate thermalization hypothesis has recently been proposed as a universal concept and has attracted considerable attention. So far this concept is, as the name states, hypothetical. The majority of attempts to overcome this hypothetical character are based on exact diagonalization, which implies for, e.g., spin systems a limitation of roughly 15 spins. In this Letter we present an approach that pushes this limit up to system sizes of roughly 35 spins, thereby going significantly beyond what is possible with exact diagonalization. A concrete application to a Heisenberg spin ladder which yields conclusive results is demonstrated.
authors.affiliation: Institute for Theoretical Physics, Technical University Braunschweig, D-38106 Braunschweig, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Steinigeweg
authors.affiliation: Department of Physics, University of Osnabrück, D-49069 Osnabrück, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Khodja
authors.affiliation: Department of Physics, University of Osnabrück, D-49069 Osnabrück, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Niemeyer
authors.affiliation: Dahlem Center for Complex Quantum Systems, Freie Universität Berlin, D-14195 Berlin, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Gogolin
authors.affiliation: Department of Physics, University of Osnabrück, D-49069 Osnabrück, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Gemmer