# Exciton transport enhancement across quantum Su-Schrieffer-Heeger lattices with quartic nonlinearity

## TL;DR

This paper investigates how weak quartic nonlinearities in a quantum Su-Schrieffer-Heeger lattice can significantly enhance exciton transport, enabling transitions from localized to delocalized conduction.

## Contribution

It identifies a dominant nonlinear correction that enhances exciton conduction, demonstrating the potential to control transport properties via lattice nonlinearities.

## Key findings

- Quartic nonlinearities lead to strong exciton transport enhancement.
- Nonlinear corrections induce transitions from localized to delocalized transport.
- Weak nonlinearities can significantly modify exciton conduction.

## Abstract

In the present work we discuss the propagation of excitons across a one-dimensional Su-Schrieffer-Heeger lattice, which possesses both harmonic oscillations and weak quartic anharmonicities. When quantizing these vibrational degrees of freedom we identify several phonon-conserving nonlinearities, each one with a different impact on the excitonic transport. Our analysis identifies a dominant nonlinear correction to the phonon hopping which leads to a strong enhancement of exciton conduction compared to a purely linear vibrational dynamics. Thus quartic lattice nonlinearities can be exploited to induce transitions from localized to delocalized transport, even for very weak amplitudes.