Trap Mediated Energy Transport via Vibronic Resonance

TL;DR

This paper introduces a method to analyze vibronic resonance in energy transfer, revealing how specific vibrational motions facilitate trap-mediated transfer in complex systems.

Contribution

It derives effective normal modes to simplify high-dimensional vibronic Hamiltonians, enabling detailed insight into vibrational motions promoting energy transfer.

Findings

Vibronic resonance can convert traps into conduits for energy transfer.

Normal mode analysis reveals specific vibrational motions that promote energy transfer.

The approach reduces computational complexity while providing physical insights.

Abstract

Controlling energy transfer through vibronic resonance is an interesting possibility. Exact treatment of non-adiabatic vibronic coupling is necessary to fully capture its role in driving energy transfer. However, exact treatment of vibrations in extended systems is expensive, sometimes requiring oversimplifying approximations to reduce vibrational dimensionality, and do not provide physical insights into which specific vibrational motions promote energy transport. Here we derive effective normal modes for excitonically coupled aggregates which reduce the overall high-dimensional vibronic Hamiltonian into independent one-dimensional Hamiltonians. Applying this approach on a trimer toy model, we demonstrate trap-mediated energy transport between electronically uncoupled sites. Bringing uncoupled sites into vibronic resonance converts the `trap' into a `conduit' for population transfer, while simultaneously minimizing trapped excitations. Visualizing energy transfer along the aggregate normal modes provides non-intuitive insights into which specific vibrational motions allow for trap-mediated energy transport by promoting vibronic mixing.