title: Vibrations and diverging length scales near the unjamming transition.
abstract: We numerically study the vibrations of jammed packings of particles interacting with finite-range, repulsive potentials at zero temperature. As the packing fraction phi is lowered towards the onset of unjamming at phi(c), the density of vibrational states approaches a nonzero value in the limit of zero frequency. For phi >phi(c), there is a crossover frequency, omega* below which the density of states drops towards zero. This crossover frequency obeys power-law scaling with phi-phi(c). Characteristic length scales, determined from the dominant wave vector contributing to the eigenmode at omega*, diverge as power laws at the unjamming transition.
authors.affiliation: James Franck Institute, University of Chicago, Chicago, IL 60637, USA.
authors.forename: Leonardo E
authors.initials: LE
authors.lastname: Silbert
authors.forename: Andrea J
authors.initials: AJ
authors.lastname: Liu
authors.forename: Sidney R
authors.initials: SR
authors.lastname: Nagel