Investigation of apparent violation of the second law of thermodynamics in quantum transport studies

Department of Electronic Structures, Faculty of Mathematics and Physics Charles University - Ke Karlovu 5, 121 16 Prague, Czech Republic

Corresponding author: tno@mag.mff.cuni.cz

Received: 26 April 2002
Accepted: 7 June 2002

Abstract

We consider a model for stationary electronic transport through a one-dimensional chain of two leads attached to a perturbed central region (quantum dot) in the regime where the theory proposed recently by Čápek for a similar model of phonon transport predicts the striking phenomenon of a permanent current between the leads. We show that Čápek's results based on a rigorous but asymptotic Davies theory differ from direct transport calculations that yield, in full agreement with the second law of thermodynamics, zero current. We find the permanent current to be within the error of the asymptotic expansion for finite couplings, and identify cancelling terms of the same order.