Chemical reactions induced by oscillating external fields in weak thermal environments

Abstract

Chemical reaction rates must increasingly be determined in systems that evolve under the control of external stimuli. In these systems, when a reactant population is induced to cross an energy barrier through forcing from a temporally varying external field, the transition state that the reaction must pass through during the transformation from reactant to product is no longer a fixed geometric structure, but is instead time-dependent. For a periodically forced model reaction, we develop a recrossing-free dividing surface that is attached to a transition state trajectory [T. Bartsch, R. Hernandez, and T. Uzer, Phys. Rev. Lett. 95, 058301 (2005)]. We have previously shown that for single-mode sinusoidal driving, the stability of the time-varying transition state directly determines the reaction rate [G. T. Craven, T. Bartsch, and R. Hernandez, J. Chem. Phys. 141, 041106 (2014)]. Here, we extend our previous work to the case of multi-mode driving waveforms. Excellent agreement is observed between the rates predicted by stability analysis and rates obtained through numerical calculation of the reactive flux. We also show that the optimal dividing surface and the resulting reaction rate for a reactive system driven by weak thermal noise can be approximated well using the transition state geometry of the underlying deterministic system. This agreement persists as long as the thermal driving strength is less than the order of that of the periodic driving. The power of this result is its simplicity. The surprising accuracy of the time-dependent noise-free geometry for obtaining transition state theory rates in chemical reactions driven by periodic fields reveals the dynamics without requiring the cost of brute-force calculations.

References in corpus (11)

• Wigner's Dynamical Transition State Theory in Phase Space: Classical and Quantum
• The Transition State in a Noisy Environment
• Stochastic Transition States: Reaction Geometry amidst Noise
• Simple models for two-dimensional tunable colloidal crystals in rotating ac electric fields
• Identifying reactive trajectories using a moving transition state
• Chaotic Dynamics in Multidimensional Transition States
• Transition state trajectory stability determines barrier crossing rates in chemical reactions induced by time-dependent oscillating fields
• Persistence of transition state structure in chemical reactions driven by fields oscillating in time
• Reaction rate calculation with time-dependent invariant manifolds
• Measuring disorder in irreversible decay processes
• Transition State Theory for dissipative systems without a dividing surface

Cited by in corpus (7)

• Electron transfer across a thermal gradient
• Invariant Manifolds and Rate Constants in Driven Chemical Reactions
• Energy transport between heat baths with oscillating temperatures
• Phase-space resolved rates in driven multidimensional chemical reactions
• Neural network approach for the dynamics on the normally hyperbolic invariant manifold of periodically driven systems
• Controlling reaction dynamics in chemical model systems through external driving
• Dynamics and bifurcations on the normally hyperbolic invariant manifold of a periodically driven system with rank-1 saddle