1 Department of Micro- and Nanotechnology, Technical University of Denmark2 Theoretical Nanoelectronics, Department of Micro- and Nanotechnology, Technical University of Denmark3 Center for Nanostructured Graphene, Center, Technical University of Denmark4 Queen's University Belfast5 Huazhong University of Science and Technology6 University of Copenhagen7 Queen's University Belfast8 Huazhong University of Science and Technology
We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that-with the help of background literature-should be accessible to physics undergraduates. The discussion aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current-the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant features at the wire surface, making it a candidate for the nucleation of current-driven structural transformations and failure. Finally we discuss the problem of force noise and the limitations of Ehrenfest dynamics.
European Journal of Physics, 2014, Vol 35, Issue 6