Simulating Exciton Transport with Complex Absorbing Potentials

TL;DR

This paper presents a stochastic framework using complex absorbing potentials to model exciton transport in large molecular aggregates, revealing how topology and disorder affect energy transfer efficiency.

Contribution

The authors develop a novel CAPs-based approach for simulating exciton dynamics and classify transport behavior based on molecular packing in 2D aggregates.

Findings

System size and defects significantly influence exciton transport.

Aggregate topology determines energy transfer efficiency.

The framework guides design of materials with improved energy transport.

Abstract

We introduce a stochastic framework based on complex absorbing potentials (CAPs) to investigate exciton transport in large molecular aggregates. Within this approach, CAPs act as non-Hermitian reservoirs and sinks that enable effective measurement of transport efficiency. We apply this framework to cyanine dye aggregates and examine how vacancy defects and system size influence exciton dynamics in two-dimensional sheets and quasi-one-dimensional tubes. We also introduce a CAPs-based classification scheme that links molecular packing in 2D aggregates to transport behavior. Our results demonstrate how aggregate topology and structural disorder govern exciton dynamics and provide guidance for designing materials with enhanced energy transport.