Abstract

Single-atom and single-molecule junctions represent the ultimate limit to the miniaturization of electrical circuits. They are also ideal platforms for testing quantum transport theories that are required to describe charge and energy transfer in novel functional nanometer-scale devices.

In this presentation, I will review the recent theoretical progress of my group towards the description of elastic and inelastic charge transport in molecular junctions as well as thermoelectric phenomena. I will discuss results on inelastic electron tunneling spectra [1,2] and the thermopower of atomic and molecular junctions [3-6] before I will come to a full ab-initio characterization of their thermoelectric figure of merit including both electronic and phononic contributions [7]. Finally, I will present recent combined experimental and theoretical efforts to understand the heat dissipation in atomic-scale junctions [8,9]. The revealed close relation between heat dissipation and thermopower provides general strategies for exploring fundamental phenomena such as the Peltier effect or the impact of quantum interference on the Joule heating of molecular junctions.