Steady-state thermodynamics of non-interacting transport beyond weak coupling
Institut für Theoretische Physik, Technische Universität Berlin - Hardenbergstrasse 36, D-10623 Berlin, Germany
Received: 28 April 2015
Accepted: 12 June 2015
We investigate the thermodynamics of simple (non-interacting) transport models beyond the scope of weak coupling. For a single fermionic or bosonic level —tunnel-coupled to two reservoirs—exact expressions for the stationary matter and energy current are derived from the solutions of the Heisenberg equations of motion. The positivity of the steady-state entropy production rate is demonstrated explicitly. Finally, for a configuration in which particles are pumped upwards in chemical potential by a downward temperature gradient, we demonstrate that the thermodynamic efficiency of this process decreases when the coupling strength between system and reservoirs is increased, as a direct consequence of the loss of a tight coupling between energy and matter currents.
PACS: 72.10.Bg – General formulation of transport theory / 05.30.Fk – Fermion systems and electron gas / 05.30.Jp – Boson systems
© EPLA, 2015