Interchain versus intrachain hole transmission through desoxyribonucleic acid molecular wires

TL;DR

This paper introduces a simplified method for calculating current-voltage responses in DNA molecular wires, revealing that sequence and intrachain interactions significantly influence hole transport.

Contribution

The authors develop a new eigenvalue-based approach for transmission calculations that avoids complex Green's function constructions, simplifying analysis of DNA conductivity.

Findings

Sequence significantly affects DNA hole transport.

Intrachain transport dominates over interchain transport.

Hole transmission is insensitive to interchain fluctuations.

Abstract

We present a methodology for computing the current-voltage response of a molecular wire within the Landauer-Buttiker formalism based upon transforming the cummulative transmission probability into an eigenvalue problem. The method is extremely simple to apply since does not involve construction of the molecular Greens function, and hence avoids the use of complex integration contours to avoid poles. We use this method to study the effect of base-pair sequence on the conductivity of holes in DNA chains containing A-T bridges between guanine chains. Our results indicate that sequence plays a substantial role in ballistic transport via tunneling resonances tuned by sequence and interchain interactions. We also find that ballistic transport is dominated by intrachain transport and that hole transmission is insensitive to interchain fluctuations.