Thermal activation at moderate-to-high and high damping: finite barrier effects and force spectroscopy

TL;DR

This paper investigates thermal escape in high damping regimes, providing a formula that accounts for finite barrier effects, and applies these findings to force spectroscopy, enhancing understanding of escape rates and mean first passage times.

Contribution

It introduces a new formula for thermal escape that incorporates finite barrier effects and extends analysis across the full damping range, with applications to force spectroscopy.

Findings

The formula matches numerical results well across damping regimes.

Finite barrier effects significantly influence escape rates.

Force spectroscopy predictions vary with different theoretical approaches.

Abstract

We study the thermal escape problem in the moderate-to-high and high damping regime of a system with a parabolic barrier. We present a formula that matches our numerical results accounting for finite barrier effects, and compare it with previous works. We also show results for the full damping range. We quantitatively study some aspects on the relation between mean first passage time and the definition of a escape rate. To finish we apply our results and considerations in the framework of force spectroscopy problems. We study the differences on the predictions using the different theories and discuss the role of $\gamma \dot{F}$ as the relevant parameter at high damping.