Formally exact, arbitrarily scalable simulations of exciton dynamics in molecular materials

TL;DR

This paper introduces adHOPS, a scalable and exact simulation method for exciton dynamics in large molecular systems, enabling mesoscale quantum dynamics modeling with size-invariant computational cost.

Contribution

The authors develop an adaptive HOPS algorithm that achieves formally exact, size-invariant simulations of exciton dynamics in molecular materials.

Findings

Demonstrated simulation of exciton diffusion in chains of up to 1000 molecules

Provided proof-of-principle calculations validating the method's accuracy

Achieved size-invariant computational scaling for mesoscale quantum dynamics

Abstract

Excited state carriers, such as excitons, can diffuse on the 100 nm to micron length scale in molecular materials, but they only delocalize over short length scales due to coupling between electronic and vibrational degrees-of-freedom. Here, we leverage the locality of excitons to adaptively solve the hierarchy of pure states equations (HOPS). We demonstrate that our adaptive HOPS (adHOPS) methodology provides a formally exact and size-invariant (i.e. O(1)) scaling algorithm for simulating mesoscale quantum dynamics. We provide proof-of-principle calculations for exciton diffusion on linear chains containing up to 1000 molecules.