First-passage time theory of activated rate chemical processes in electronic molecular junctions

摘要: Confined nanoscale spaces, electric fields and tunneling currents make the molecular electronic junction an experimental device for discovery of new, out-of-equilibrium chemical reactions. Reaction-rate theory current-activated reactions is developed by combining a Keldysh nonequilibrium Green's functions treatment electrons, Fokker-Planck description reaction coordinate, Kramers' first-passage time calculations. The NEGF provide adiabatic potential as well diffusion coefficient temperature with local dependence on coordinate. Van Kampen's equation, which describes Brownian particle moving in external inhomogeneous medium position-dependent friction coefficient, used to obtain analytic expression time. applied several transport scenarios: single, coordinate dependent orbital, model diatomic junction. We demonstrate natural emergence Landauer's blowtorch effect result interplay between configuration viscosity coefficients. resultant localized heating conjunction bond-deformation due current-induced forces are shown be determining factors when considering rates; each from highly tunable parameters within system.