Exit dynamics from Morse potential under thermal fluctuations

TL;DR

This paper investigates the escape dynamics of a Brownian particle in a Morse potential under thermal fluctuations, deriving analytical expressions and validating them with numerical simulations to understand temperature and viscosity effects.

Contribution

It introduces an approximate analytical expression for the reaction rate of a particle in Morse potential considering temperature-dependent pre-factors, supported by numerical validation.

Findings

Reaction rate depends on temperature and viscosity.

Analytical approximation matches numerical simulations.

Temperature influences the pre-factor in Arrhenius equation.

Abstract

We study the dynamics of a Brownian particle in Morse potential under thermal fluctuations, modeled by Gaussian white noise whose amplitude depends on absolute temperature. Dynamics of such a particle is investigated by numerically integrating the corresponding Langevin equation. From the mean first passage time (escape time), we study the dependence of Kramer's rate on temperature and viscosity of the medium. An approximate expression for the reaction rate is found by solving differential equation for the mean first passage time. The expression shows a temperature dependent pre-factor for the Arrhenius equation. Our numerical simulations are in agreement with analytical approximations.