Intermittency, aging and record fluctuations
arXiv:cond-mat/0403212 · doi:10.1209/epl/i2004-10376-1
Abstract
Aging in spin glasses is analyzed via the Probability Density Function (PDF) of the heat transfer between system and bath over a small time . The PDF contains a Gaussian part, describing reversible fluctuations, and an exponential tail caused by intermittent events. We find that the relative weight of these two parts depends, for fixed , on the ratio of the total sampling time to the age . Fixing this ratio, the intensity of the intermittent events is proportional to and independent of the temperature. The Gaussian part has a variance with the same temperature dependence as the variance of the equilibrium energy in a system with an exponential density of states. All these observations are explained assuming that, for any , intermittent events are triggered by local energy fluctuations exceeding those previously occurred.
7 pages, 4 figs Final, extended version to appear in Europhysics Letter