Crucial effect of transverse vibrations on the transport through polymer chains

TL;DR

This paper demonstrates that transverse acoustic vibrations significantly impact electron and exciton transport in polymers, causing strong decoherence and a quantum phase transition that suppresses transport at low temperatures.

Contribution

It reveals the crucial role of transverse vibrations in polymer transport, highlighting their stronger effects compared to longitudinal vibrations and explaining recent experimental observations.

Findings

Transverse vibrations cause a polaron effect and decoherence in polymer transport.

A quantum phase transition leads to transport suppression at zero temperature.

Temperature dependence of decoherence rate varies with site interactions, matching experimental data.

Abstract

The low temperature transport of electron, or vibrational or electronic exciton towards polymer chains turns out to be dramatically sensitive to its interaction with transverse acoustic vibrations. We show that this interaction leads to substantial polaron effect and decoherence, which are generally stronger than those associated with longitudinal vibrations. For site-dependent interactions transverse phonons form subohmic bath leading to the quantum phase transition accompanied by full suppression of the transport at zero temperature and fast decoherence characterized by temperature dependent rate of temperature to the power of two thirds at low temperature while this rate rate ois proportional to the squared temperature for site-independent interactions. The latter dependence was used to interpret recent measurements of temperature dependent vibrational energy transport in polyethylene glycol oligomers.