@article{7766, abstract = {We study the vibrational properties near a free surface of disordered spring networks derived from jammed sphere packings. In bulk systems, without surfaces, it is well understood that such systems have a plateau in the density of vibrational modes extending down to a frequency scale ω*. This frequency is controlled by ΔZ = 〈Z〉 − 2d, the difference between the average coordination of the spheres and twice the spatial dimension, d, of the system, which vanishes at the jamming transition. In the presence of a free surface we find that there is a density of disordered vibrational modes associated with the surface that extends far below ω*. The total number of these low-frequency surface modes is controlled by ΔZ, and the profile of their decay into the bulk has two characteristic length scales, which diverge as ΔZ−1/2 and ΔZ−1 as the jamming transition is approached.}, author = {Sussman, Daniel M. and Goodrich, Carl Peter and Liu, Andrea J. and Nagel, Sidney R.}, issn = {1744-683X}, journal = {Soft Matter}, number = {14}, pages = {2745--2751}, publisher = {Royal Society of Chemistry}, title = {{Disordered surface vibrations in jammed sphere packings}}, doi = {10.1039/c4sm02905d}, volume = {11}, year = {2015}, }