title: Long-range strain correlations in sheared colloidal glasses.
abstract: Glasses behave as solids on experimental time scales due to their slow relaxation. Growing dynamic length scales due to cooperative motion of particles are believed to be central to this slow response. For quiescent glasses, however, the size of the cooperatively rearranging regions has never been observed to exceed a few particle diameters, and the observation of long-range correlations has remained elusive. Here, we provide direct experimental evidence of long-range correlations during the deformation of a dense colloidal glass. By imposing an external stress, we force structural rearrangements, and we identify long-range correlations in the fluctuations of microscopic strain and elucidate their scaling and spatial symmetry. The applied shear induces a transition from homogeneous to inhomogeneous flow at a critical shear rate, and we investigate the role of strain correlations in this transition.
authors.affiliation: Van der Waals-Zeeman Institute, University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands.
authors.forename: Vijayakumar
authors.initials: V
authors.lastname: Chikkadi
authors.forename: Gerard
authors.initials: G
authors.lastname: Wegdam
authors.forename: Daniel
authors.initials: D
authors.lastname: Bonn
authors.forename: Bernard
authors.initials: B
authors.lastname: Nienhuis
authors.forename: Peter
authors.initials: P
authors.lastname: Schall