Role of heating and current-induced forces in the stability of atomic wires

TL;DR

This paper explores how local heating and current-induced forces affect the stability of aluminum atomic wires, showing that heating is manageable at low biases but forces cause break-up at higher biases, aligning with experimental data.

Contribution

It provides a detailed analysis of the relative impacts of heating and forces on wire stability, highlighting the dominant role of current-induced forces at high biases.

Findings

Heating increases with wire length but remains low with good thermal contact.

Current-induced forces grow with bias and can cause wire break-up around 1 V.

Local heating promotes low-bias instabilities, while forces dominate at high biases.

Abstract

We investigate the role of local heating and forces on ions in the stability of current-carrying aluminum wires. We find that heating increases with wire length due to a red shift of the frequency spectrum. Nevertheless, the local temperature of the wire is relatively low for a wide range of biases provided good thermal contact exists between the wire and the bulk electrodes. On the contrary, current-induced forces increase substantially as a function of bias and reach bond-breaking values at about 1 V. These results suggest that local heating promotes low-bias instabilities if dissipation into the bulk electrodes is not efficient, while current-induced forces are mainly responsible for the wire break-up at large biases. We compare these results to experimental observations.