Out of equilibrium generalized Stokes-Einstein relation: determination of the effective temperature of an aging medium

Noelle Pottier (1, 2)

1 MSC - Matière et Systèmes Complexes
2 GPS - Groupe de Physique des Solides

We analyze in details how the anomalous drift and diffusion properties of a particle evolving in an aging medium can be interpreted in terms of an effective temperature of the medium. From an experimental point of view, independent measurements of the mean-square displacement and of the mobility of a particle immersed in an aging medium such as a colloidal glass give access to an out of equilibrium generalized Stokes-Einstein relation, from which the effective temperature of the medium can eventually be deduced. We illustrate the procedure on a simple model with power-law behaviours.

Mots clés: Fluctuation phenomena; Random processes; Noise and Brown- ian motion; Stochastic processes

Domaines: Mécanique statistique [cond-mat.stat-mech]; Matière Molle [cond-mat.soft]

Noelle Pottier. Out of equilibrium generalized Stokes-Einstein relation: determination of the effective temperature of an aging medium. Physica A: Statistical Mechanics and its Applications, 2005, 345 (3-4), pp.472-484. ⟨10.1016/j.physa.2004.07.019⟩. ⟨hal-00134697⟩