Current-induced forces: a simple derivation

Abstract

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.

published version

References in corpus (8)

• Molecular Transport Junctions: Vibrational Effects
• Inelastic transport theory from first-principles: methodology and applications for nanoscale devices
• Scattering theory of current-induced forces in mesoscopic systems
• Current-induced atomic dynamics, instabilities, and Raman signals: Quasi-classical Langevin equation approach
• From tunneling to contact: Inelastic signals in an atomic gold junction
• Laser-like vibrational instability in rectifying molecular conductors
• Scattering theory of adiabatic reaction forces due to out-of-equilibrium quantum environments
• An ignition key for atomic-scale engines