title: Evidence for non-conservative current-induced forces in the breaking of Au and Pt atomic chains.
abstract: This experimental work aims at probing current-induced forces at the atomic scale. Specifically it addresses predictions in recent work regarding the appearance of run-away modes as a result of a combined effect of the non-conservative wind force and a 'Berry force'. The systems we consider here are atomic chains of Au and Pt atoms, for which we investigate the distribution of break down voltage values. We observe two distinct modes of breaking for Au atomic chains. The breaking at high voltage appears to behave as expected for regular break down by thermal excitation due to Joule heating. However, there is a low-voltage breaking mode that has characteristics expected for the mechanism of current-induced forces. Although a full comparison would require more detailed information on the individual atomic configurations, the systems we consider are very similar to those considered in recent model calculations and the comparison between experiment and theory is very encouraging for the interpretation we propose.
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, PO Box 9504, 2300 RA Leiden, Netherlands.
authors.forename: Carlos
authors.initials: C
authors.lastname: Sabater
authors.affiliation: Departamento de Física Aplicada, Universidad de Alicante, Campus de San Vicente del Raspeig, E-03690 Alicante, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Untiedt
authors.affiliation: Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, PO Box 9504, 2300 RA Leiden, Netherlands.
authors.forename: Jan M
authors.initials: JM
authors.lastname: van Ruitenbeek
keywords: atomic chain; atomic-size contacts; break junctions; current-induced forces