Nonequilibrium thermodynamics and information theory: Foundations and relaxing dynamics

Bernhard Altaner

Published 2017-02-25Version 1

In this work, we present a didactic approach to nonequilibrium thermodynamics based on information theory. For a generally time-dependent open-system setup, where conserved extensive quantities can be exchanged with an environment, we consistently define non-equilibrium potentials, state functions and process quantities. As our main result, we show that a single natural information-theoretic assumption about the relaxation process is equivalent to the well-known thermodynamic process inequalities: the Second Law of Thermodynamics, the law of exergy increase, a modified non-equilibrium work--free-energy inequality and Landauer's principle. Our theory reproduces previous results for closed driven systems, but additionally highlights new terms which only appear in open driven systems or in the presence of changing environments. In particular, our analysis highlights the special role of energy and sheds light on the peculiar non-isothermal corrections that appear if the temperature of a heat bath is varied during a thermodynamic process.