Nonconservative dynamics in long atomic wires

TL;DR

This paper investigates how nonconservative current-induced forces affect ion dynamics in metallic nanowires, revealing their significant impact in short wires and their diminishing influence as system length increases.

Contribution

It demonstrates the importance of nonconservative forces in short nanowires and provides simple models to predict their effects and guide stable quantum wire design.

Findings

Nonconservative forces significantly influence ion dynamics in short nanowires.

The impact of these forces decreases with increasing wire length.

Simple models can predict the dependence on bias and ion mass.

Abstract

The effect of nonconservative current-induced forces on the ions in a defect-free metallic nanowire is investigated using both steady-state calculations and dynamical simulations. Non-conservative forces were found to have a major influence on the ion dynamics in these systems, but their role in increasing the kinetic energy of the ions decreases with increasing system length. The results illustrate the importance of nonconservative effects in short nanowires and the scaling of these effects with system size. The dependence on bias and ion mass can be understood with the help of a simple pen and paper model. This material highlights the benefit of simple preliminary steady-state calculations in anticipating aspects of brute-force dynamical simulations, and provides rule of thumb criteria for the design of stable quantum wires.