Unraveling current-induced dissociation mechanisms in single-molecule junctions

Understanding current-induced bond rupture in single-molecule junctions is both of fundamental interest and a prerequisite for the design molecular junctions, which are stable at higher bias voltages. In this work, we use fully quantum mechanical method based on hierarchical master equation approach to analyze dissociation mechanisms junctions. Considering wide range transport regimes, from off-resonant resonant, non-adiabatic adiabatic transport, weak strong vibronic coupling, our systematic study identifies three mechanisms. intermediate coupling regime, dominant mechanism stepwise vibrational ladder climbing. For induced via multi-quantum excitations triggered either by single electronic transition high voltages or multiple transitions low biases. Furthermore, influence relaxation dynamics analyzed strategies improving stability discussed.