# Quantum transport through a coupled non-linear exciton-phonon system

## TL;DR

This study investigates how finite temperature lattice vibrations and anharmonicity influence quantum wavepacket transport in a coupled nonlinear exciton-phonon system, revealing temperature-dependent transport suppression and conditions for enhanced transmission.

## Contribution

It provides a detailed numerical analysis of temperature and anharmonicity effects on quantum transport in nonlinear exciton-phonon systems, highlighting new regimes of wavepacket dynamics.

## Key findings

- Finite temperature suppresses ballistic transport.
- Small anharmonicity causes self-trapping and subdiffusive leakage.
- Higher anharmonicity enhances transmission, reducing barriers.

## Abstract

Wavepacket transport across a nonlinear region is studied numerically at zero and finite temperatures. In contrary to the zero temperature case which demonstrates ballistic transport, finite temperature lattice vibrations suppresses the transport drastically. The interface between the linear and the nonlinear chain plays the role of a high barrier at finite temperature when anharmonicity factor is small compared to the typical inverse cubic interatomic distance. Inverse participation ratio of the central region shows that for small anharmonicity and finite temperatures lattice vibrations give rise to self-trapping in the nonlinear chain which lasts for considerable times with a subdiffusive leakage of the wavepacket, almost equally, to both leads. The scenario changes when the anharmonicity becomes comparable with average inverse cubic interatomic distances as the lattice dynamics gives a profound boost to the transmission and starts to be almost transparent for the incoming pulse.