Heat and work in time-dependent strong coupling


A time-dependent change of the interaction between a system and a bath can be thought of as the result of the action of external controller, and its effect could hence be a form of work. Yet the only effects of the interaction between a system and a bath are supposed to be heat, so how can a change of heat be work? I will discuss these issues in the framework of the solvable model of a system coupled to a bath of harmonic oscillators (Zwanzig model). I will show a new form of work proportional to the rate of change of the system-bath coupling which is entirely dissipated into heat. I will discuss how this work enters Jarzynski Equality and how it solves certain problems in the quantum-classical correspondence for heat identified in an earlier contribution (Aurell \& Eichhorn, 2015). The talk is based on arXiv:1705.07811.