Thermal decay rates for an asymmetric cusped barrier at strong friction

Abstract

The thermal decay of a metastable state over an asymmetric cusped barrier in the regime of overdamping (strong friction) is considered. This seems to be of importance for the nanoscale experiments on pulling polymeric molecules. The decay process is simulated numerically through computer solving of the Langevin equation. The quasistationary rates RD , as well as the mean lifetimes and transient times, are extracted from the numerical time-dependent rates Rn (t). The impact of the backscattering on the value of RD is discussed. The approximate analytical decay rate is derived for the asymmetric cusped barrier. The numerical results are confronted with this formula and with another analytical formula (the integral Kramers rate) available in the literature.