title: Nonconservative current-induced forces: A physical interpretation.
abstract: We give a physical interpretation of the recently demonstrated nonconservative nature of interatomic forces in current-carrying nanostructures. We start from the analytical expression for the curl of these forces, and evaluate it for a point defect in a current-carrying system. We obtain a general definition of the capacity of electrical current flow to exert a nonconservative force, and thus do net work around closed paths, by a formal noninvasive test procedure. Second, we show that the gain in atomic kinetic energy over time, generated by nonconservative current-induced forces, is equivalent to the uncompensated stimulated emission of directional phonons. This connection with electron-phonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.
authors.affiliation: Atomistic Simulation Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN, UK.
authors.forename: Tchavdar N
authors.initials: TN
authors.lastname: Todorov
authors.forename: Daniel
authors.initials: D
authors.lastname: Dundas
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Paxton
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Horsfield