Backbone-induced semiconducting behavior in short DNA wires

TL;DR

This paper introduces a model Hamiltonian that explains the semiconducting behavior observed in short DNA molecules by focusing on the hybridization of pi orbitals and backbone interactions, aligning well with experimental findings.

Contribution

It presents a minimal parameter model that captures the semiconducting gap and molecular resonances in short DNA wires, advancing understanding of charge transport mechanisms.

Findings

Model predicts a gap in current-voltage characteristics.

Results agree with experimental semiconducting behavior.

Accurately describes molecular resonances affecting current.

Abstract

We propose a model Hamiltonian for describing charge transport through short homogeneous double stranded DNA molecules. We show that the hybridization of the overlapping pi orbitals in the base-pair stack coupled to the backbone is sufficient to predict the existence of a gap in the nonequilibrium current-voltage characteristics with a minimal number of parameters. Our results are in a good agreement with the recent finding of semiconducting behavior in short poly(G)-poly(C) DNA oligomers. In particular, our model provides a correct description of the molecular resonances which determine the quasi-linear part of the current out of the gap region.