THERMALIZATION OF AN ELECTRON-PHONON SYSTEM IN A NONEQUILIBRIUM STATECHARACTERIZED BY FRACTAL DISTRIBUTION OF PHONON EXCITATIONS

The thermalization of an electron-phonon system in a nonequilibrium st ate characterized by a fractal distribution of phonon excitations is c alculated in a novel way, which takes into account the unusual, invers e power-law type distribution of phonon energies. The calculations are done from the first principles, based on a nonequilibrium statistical operator combined with the recently proposed generalized, nonextensiv e thermostatistics. As a result the usual linear (Newtonian) energy tr ansfer rate (Q) over dot proportional to - (T-p-T-e) is replaced by a nonlinear rate (Q) over dot proportional to - (T-p(q)-T-e(q)), where q greater than or equal to 1 is related to the fractality of the excita tion energy distribution. Consequences of this result for a thermal re laxation of the nonequilibrium phonon system are discussed.