title: Dynamical correlations near dislocation jamming.
abstract: Dislocation assemblies exhibit a jamming or yielding transition at a critical external shear stress value σ=σ{c}. Here we study the heterogeneous and collective nature of dislocation dynamics within a crystal plasticity model close to σ{c}, by considering the first-passage properties of the dislocation dynamics. As the transition is approached in the moving phase, the first-passage time distribution exhibits scaling, and a related peak dynamical susceptibility χ{4}{*} diverges as χ{4}{*}∼(σ-σ{c}){-α}, with α≈1.1. We relate this scaling to an avalanche description of the dynamics. While the static structural correlations are found to be independent of the external stress, we identify a diverging dynamical correlation length ξ{y} in the direction perpendicular to the dislocation glide motion.
authors.affiliation: ISI Foundation, Viale S. Severo 65, 10133 Torino, Italy.
authors.forename: Lasse
authors.initials: L
authors.lastname: Laurson
authors.forename: M-Carmen
authors.initials: MC
authors.lastname: Miguel
authors.forename: Mikko J
authors.initials: MJ
authors.lastname: Alava