title: Influence of boundary conditions on yielding in a soft glassy material.
abstract: The yielding behavior of a sheared Laponite suspension is investigated within a 1 mm gap under two different boundary conditions. No-slip conditions, ensured by using rough walls, lead to shear localization as already reported in various soft glassy materials. When apparent wall slip is allowed using a smooth geometry, the sample breaks up into macroscopic solid pieces that get slowly eroded by the surrounding fluidized material up to the point where the whole sample is fluid. Such a drastic effect of boundary conditions on yielding suggests the existence of some macroscopic characteristic length that could be connected to cooperativity effects in jammed materials under shear.
authors.affiliation: Laboratoire de Physique, Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS UMR 5672 46 allée d'Italie, 69364 Lyon cedex 07, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gibaud
authors.forename: Catherine
authors.initials: C
authors.lastname: Barentin
authors.forename: Sébastien
authors.initials: S
authors.lastname: Manneville