Vibronic Dephasing Model for Coherent-to-Incoherent Crossover in DNA

TL;DR

This paper introduces a vibronic dephasing model to study the transition from coherent to incoherent charge transport in DNA, providing a physically grounded approach that aligns with experimental data.

Contribution

It presents a new vibronic dephasing model for DNA charge transport, offering insights into length-dependent behavior and crossover phenomena, and compares it with existing models.

Findings

The model captures the crossover from coherent to incoherent transport.

Results align with experimental measurements of DNA conductance.

The approach improves understanding of temperature-dependent charge transport.

Abstract

In this work we investigate the interplay between coherent and incoherent charge transport in cytosine-guanine (GC) rich DNA molecules. Our objective is to introduce physically grounded approach to dephasing in large molecules and to understand the length dependent charge transport characteristics and especially the crossover from coherent tunneling to incoherent hopping regime at different temperatures. Therefore, we apply the vibronic dephasing model and compare the results to the B\"uttiker probe model which is commonly used to describe decoherence effects in charge transport. Using the full ladder model and simplified 1D model of DNA, we consider molecular junctions with alternating and stacked GC sequences and compare our results to recent experimental measurements.