Thermal decay rates of an activated complex in a driven model chemical reaction

TL;DR

This paper investigates how thermal noise and external driving influence the decay rates of activated complexes in driven chemical reactions, linking temperature dependence to phase space dynamics on the NHIM.

Contribution

It introduces a framework connecting non-dissipative phase space decay rates to thermal decay behavior, demonstrating control of decay rates through external driving.

Findings

Decay rates fluctuate under thermal noise.

Temperature dependence relates to phase space decay rate distribution.

External driving can modulate decay rate temperature dependence.

Abstract

Recent work has shown that in a non-thermal, multidimensional system, the trajectories in the activated complex possess different instantaneous and time-averaged reactant decay rates. Under dissipative dynamics, it is known that these trajectories, which are bound on the normally hyperbolic invariant manifold (NHIM), converge to a single trajectory over time. By subjecting these dissipative systems to thermal noise, we find fluctuations in the saddle-bound trajectories and their instantaneous decay rates. Averaging over these instantaneous rates results in the decay rate of the activated complex in a thermal system. We find, that the temperature dependence of the activated complex decay in a thermal system can be linked to the distribution of the phase space resolved decay rates on the NHIM in the non-dissipative case. By adjusting the external driving of the reaction, we show that it is possible to influence how the decay rate of the activated complex changes with rising temperature.