Department of Physics Papers

Document Type

Journal Article

Date of this Version

12-10-2008

Comments

Suggested Citation:
A.R. Abate and D.J. Durian. (2008). "Effective Temperatures and Activated Dynamics for a Two-Dimensional Air-Driven Granular System on Two Approaches to Jamming." Physical Review Letters. 101, 245701.

© 2008 The American Physical Society
http://dx.doi.org/10.1103/PhysRevLett.101.245701

Abstract

We present experiments on several distinct effective temperatures in a granular system at a sequence of increasing packing densities and at a sequence of decreasing driving rates. This includes single-grain measurements based on the mechanical energies of both the grains and an embedded oscillator, as well as a collective measurement based on the Einstein relation between diffusivity and mobility, which all probe different time scales. Remarkably, all effective temperatures agree. Furthermore, mobility data along the two trajectories collapse when plotted vs effective temperature and exhibit an Arrhenius form with the same energy barrier as the microscopic relaxation time.

 

Date Posted: 13 January 2011

This document has been peer reviewed.