title: Dislocations jam at any density.
abstract: Crystalline materials deform in an intermittent way via dislocation-slip avalanches. Below a critical stress, the dislocations are jammed within their glide plane due to long-range elastic interactions and the material exhibits plastic response, while above this critical stress the dislocations are mobile (the unjammed phase) and the material flows. We use dislocation dynamics and scaling arguments in two dimensions to show that the critical stress grows with the square root of the dislocation density. Consequently, dislocations jam at any density, in contrast with granular materials, which only jam below a critical density.
authors.affiliation: Department of Physics, University of Illinois at Urbana-Champaign, Loomis Laboratory of Physics, 1110 West Green Street, Urbana, Illinois, 61801-3080, USA.
authors.forename: Georgios
authors.initials: G
authors.lastname: Tsekenis
authors.forename: Nigel
authors.initials: N
authors.lastname: Goldenfeld
authors.forename: Karin A
authors.initials: KA
authors.lastname: Dahmen