title: Creep and flow of glasses: strain response linked to the spatial distribution of dynamical heterogeneities.
abstract: Mechanical properties are of central importance to materials sciences, in particular if they depend on external stimuli. Here we investigate the rheological response of amorphous solids, namely colloidal glasses, to external forces. Using confocal microscopy and computer simulations, we establish a quantitative link between the macroscopic creep response and the microscopic single-particle dynamics. We observe dynamical heterogeneities, namely regions of enhanced mobility, which remain localized in the creep regime, but grow for applied stresses leading to steady flow. These different behaviors are also reflected in the average particle dynamics, quantified by the mean squared displacement of the individual particles, and the fraction of active regions. Both microscopic quantities are found to be proportional to the macroscopic strain, despite the non-equilibrium and non-linear conditions during creep and the transient regime prior to steady flow.
authors.affiliation: Condensed Matter Physics Laboratory, Heinrich Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany.
authors.forename: T
authors.initials: T
authors.lastname: Sentjabrskaja
authors.affiliation: Theoretical Physics II, Heinrich Heine University, Universitätsstr. 1, 40255 Düsseldorf, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Chaudhuri
authors.affiliation: SUPA, School of Physics &Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: M
authors.initials: M
authors.lastname: Hermes
authors.affiliation: SUPA, School of Physics &Astronomy, The University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, United Kingdom.
authors.forename: W C K
authors.initials: WC
authors.lastname: Poon
authors.affiliation: Theoretical Physics II, Heinrich Heine University, Universitätsstr. 1, 40255 Düsseldorf, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Horbach
authors.affiliation: Condensed Matter Physics Laboratory, Heinrich Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany.
authors.forename: S U
authors.initials: SU
authors.lastname: Egelhaaf
authors.affiliation: Condensed Matter Physics Laboratory, Heinrich Heine University, Universitätsstr. 1, 40225 Düsseldorf, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Laurati