Abstract

Over ten years ago our group showed that interatomic forces under current flow in nanostructures are non-conservative even under ideal steady-state conditions. In other words, the forces on atoms under current are not given by the gradient of a potential, opening up the questions of what the motion of atoms under these conditions looks like and what it can and cannot do. Other researchers world-wide have joined this area, with a number of new ideas and advances. This talk will summarise our research on this problem, both in the past and at present. In the past we have investigated the resultant atomic dynamics in a variety of systems, revealing a generic effect: the continuous supply of kinetic energy to the atomic motion by the work done by the non-conservative forces, which we have called the waterwheel effect. This effect can be seen both as a constructive aspect of the current-driven dynamics opening up the possibility of atomic-scale manipulation, and as a destructive agent limiting the stability of nanoscale conductors over and above Joule heating. Most recently we have started to investigate the influence of electron-electron interactions on the waterwheel effect, with some interesting preliminary findings.