Quantum transport in electrochemical environments: influence of the Helmholtz-double layer

The controlled manipulation of charge transport on the atomic and molecular scale still is a tremendous experimental challenge. For this reason it is a very active research field in nanotechnology. One of the most successful control strategies is operating in electrochemical media. The goal of this project is to investigate the influence of the Helmholtz-double layer on the transport properties of constrictions that consist of one or very few atoms, only. To this end we closely collaborate within a consortium consisting of two theory groups - one at the KIT (North Campus, theo. physics) and one at Ulm University (theo. Chemistry) - and an experimental group at the KIT (South Campus).

In the first stage, the Ulm group works out atomistic models of the double-layer and its dependency on the potential of the electrochemical electrodes in order to achieve a simulation of contact conditions as realistically as possible. Taking these contact conditions as an input, the theory group at the KIT can calculate the current voltage characteristics and study differences of the models with respect to their transport behavior. The analysis of the theoretical modeling and the subsequent comparison with the experimental data will provide a significantly improved understanding of the interplay between the potential of the electrochemical electrodes and the transport properties of the atomic contact. We believe that our research might lead into a novel possibility to investigate the internal structure of the double layer. For this reason our project might also be of relevance for scientific questions that relate to electrochemical energy conversion and storage.