Issue
EPL
Volume 83, Number 4, August 2008
Article Number 46002
Number of page(s) 5
Section Condensed Matter: Structural, Mechanical and Thermal Properties
DOI http://dx.doi.org/10.1209/0295-5075/83/46002
Published online 04 August 2008
EPL, 83 (2008) 46002
DOI: 10.1209/0295-5075/83/46002

Lower bound on the four-point dynamical susceptibility: Direct experimental test on a granular packing

F. Lechenault1, O. Dauchot1, G. Biroli2 and J. P. Bouchaud3

1  CEA Saclay/SPEC, URA2464 - L'Orme des Merisiers, 91191 Gif-sur-Yvette, France, EU
2  CEA Saclay/SPhT, UMR2306 - L'Orme des Merisiers, 91191 Gif-sur-Yvette, France, EU
3  Science & Finance, Capital Fund Management - 6-8 Bd. Haussmann, 75009 Paris, France, EU

olivier.dauchot@cea.fr

received 12 December 2007; accepted in final form 25 June 2008; published August 2008
published online 4 August 2008

Abstract
We track the motion of a horizontally vibrated amorphous assembly of bidisperse hard disks, for densities ranging across the jamming transition. We derive on very general grounds a bound on the dynamical susceptibility in terms of the response of the dynamics to a change in density. This generalizes a similar bound recently derived for equilibrium liquids. We find that in our experimental system the bound is tight and reproduces the non-monotonic behavior of the dynamical susceptibility both in time and density across the jamming transition. The underlying scaling behavior reveals an intimate connection between anomalous diffusion and dynamical heterogeneity.

PACS
64.70.P- - Glass transitions of specific systems.
05.40.Ca - Noise.
45.70.Cc - Static sandpiles; granular compaction.

© EPLA 2008