Intermittency of glassy relaxation and the emergence of a non-equilibrium spontaneous measure in the aging regimeA. Crisanti1, 2 and F. Ritort3, 4
1 Dipartimento di Fisica, Università di Roma "La Sapienza" P.le Aldo Moro 2, I-00185 Roma, Italy
2 Istituto Nazionale Fisica della Materia, Unità di Roma and SMC P.le Aldo Moro 2, I-00185 Roma, Italy
3 Department of Physics, Faculty of Physics, University of Barcelona Diagonal 647, 08028 Barcelona, Spain
4 Department of Physics, University of California - Berkeley, CA 94720, USA
(Received 17 October 2003; accepted in final form 4 February 2004)
We consider heat exchange processes between non-equilibrium aging systems (in their activated regime) and the thermal bath in contact. We discuss a scenario where two different heat exchange processes concur in the overall heat dissipation: a stimulated fast process determined by the temperature of the bath and a spontaneous intermittent process determined by the fact that the system has been prepared in a non-equilibrium state. The latter is described by a probability distribution function (PDF) that has an exponential tail of width given by a parameter , and satisfies a fluctuation theorem (FT) governed by that parameter. The value of is proportional to the so-called effective temperature, thereby providing a practical way to experimentally measure it by analyzing the PDF of intermittent events.
64.70.Pf - Glass transitions.
05.40.-a - Fluctuation phenomena, random processes, noise, and Brownian motion.
05.70.Ln - Nonequilibrium and irreversible thermodynamics.
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