Title: Nonconservative current-induced forces: A physical interpretation
Author(s): Todorov T.N., Dundas D., Paxton A.T., Horsfield A.P.
Beilstein Journal of Nanotechnology, 2, pp. 727-733 (2011)
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 electronâphonon interactions quantifies explicitly the intuitive notion that nonconservative forces work by angular momentum transfer.