ON THE SELECTION OF THE STATE-SPACE IN NONEQUILIBRIUM THERMODYNAMICS

We address here the question of the choice and interpretation of state variables in the thermodynamical description of systems arbitrarily a way from equilibrium. It is presented a discussion of the topic in the framework of informational statistical thermodynamics, an approach ba sed on Gibbs algorithm for nonequilibrium dissipative systems, which p rovides mechano-statistical foundations to phenomenological theories o f irreversible thermodynamics. The theory is applied in the case of a particular system consisting of the mobile carriers in a highly excite d photoinjected plasma in semiconductors. The concepts and results thu s obtained are tested against experimental data in time-resolved and t ime-integrated optical laser spectroscopy. It is shown how nonequilibr ium thermodynamic variables are evidenced and measured in such experim ents. It is also discussed the influence on them of the inclusion of d issipative fluxes among the basic variables.