title: Anomalous vibrational dispersion in holographically trapped colloidal arrays.
abstract: Colloidal spheres localized in an array of harmonic wells form a thermally excited, viscously damped dynamical system capable of supporting propagating elastic waves. Experimentally realized with micrometer-scale polystyrene spheres localized in a line of holographic optical traps, the hydrodynamically coupled array's behavior is quantitatively explained by a model based on the Oseen superposition approximation. The spheres' purely dissipative coupling is predicted to mediate a crossover to a regime of underdamped propagating elastic waves with uniformly negative group velocities that has yet to be verified experimentally.
authors.affiliation: Department of Physics and Center for Soft Matter Research, New York University, New York, New York 10003, USA.
authors.forename: Marco
authors.initials: M
authors.lastname: Polin
authors.forename: David G
authors.initials: DG
authors.lastname: Grier
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Quake