  Electronic-vibrational coupling in single-molecule junctions may result in
current-induced bond rupture and is thus an important mechanism for the
stability of molecular junctions. We use the hierarchical quantum master
equation (HQME) method in combination with the quasi-classical Ehrenfest
approach for the nuclear degrees of freedom to simulate current-induced bond
rupture in single-molecule junctions. Employing generic models for molecular
junctions with dissociative nuclear potentials, we analyze the underlying
mechanisms. In particular, we investigate the dependence of the dissociation
probability on the applied bias voltage and the molecule-lead coupling
strength. The results show that an applied bias voltage can not only lead to
dissociation of the molecular junction, but under certain conditions can also
increase the stability of the molecule.
