Electromigration of a single atom along a chain of gold atoms was investigated by first-principles calculations based on the non-equilibrium Green’s-function technique combined with density-functional theory. In the case of the electromigration of a gold atom, it was found that the potential barrier along the migration pathway decreased as the applied bias voltage was increased and the migration direction was the same as that of electron flow. By considering the case of electromigration of a sulfur atom along the gold chain, it was determined that the electron flow around the migrating atom was responsible for single-atom electromigration. The calculated electromigration rate for the gold atom indicated that the electromigration took place at temperatures above room temperature.

Diffusion Processes in Single-Atom Electromigration Along a Gold Chain - First-Principles Calculations. M.Araidai, M.Tsukada: Physical Review B, 2009, 80[4], 045417