Floquet analysis for vibronically modulated electron tunneling.

Area of Science:

• Molecular Quantum Dynamics
• Electron Transfer Theory
• Spectroscopy

Background:

• Electron tunneling is a key mechanism for electron transfer (ET) in molecular systems.
• Electronic coherence and interference effects are crucial for accurate ET analysis.
• Vibronic interactions and symmetry influence ET rates, especially in forbidden pathways.

Purpose of the Study:

• To investigate the impact of infrared (IR) fields on electron transfer (ET) kinetics.
• To explore how IR irradiation modulates tunneling probabilities and ET rates.
• To theoretically and computationally analyze ET rate control via IR interaction with molecular bridges.

Main Methods:

• Application of Floquet theory to model systems under IR driving.
• Computation of electron transfer rates for symmetry-allowed and forbidden pathways.
• Analysis of vibronic interactions and their modulation by IR fields.

Main Results:

• IR fields can significantly enhance inelastic tunneling and ET rates in symmetry-forbidden systems (up to 4 orders of magnitude).
• IR driving can also suppress ET rates depending on system energetics.
• In symmetry-allowed systems, IR effects are less pronounced, with moderate enhancements (up to 34%) or suppressions (around 3%).

Conclusions:

• IR irradiation offers a powerful method for controlling electron transfer rates in molecular systems.
• The study provides the first theoretical and computational evidence of ET rate control through IR irradiation of the bridge.
• Understanding these IR-driven dynamics is crucial for designing molecular systems with tailored electronic properties.