Topological states and quantized current in helical molecules

TL;DR

This paper theoretically demonstrates that topological states can form in helical molecules under a perpendicular electric field, leading to quantized charge pumping that is robust against perturbations, with implications for biological electron transport.

Contribution

It introduces the concept of topological states in helical molecules induced by electric fields, enabling quantized current and advancing understanding of electron transport in biological systems.

Findings

Topological states appear in helical molecules under perpendicular electric fields.

Quantized current is achieved through adiabatic charge pumping with rotating electric fields.

Quantized current plateaus are robust against perturbations and vary with Fermi energy and bias.

Abstract

We report a theoretical study of electron transport along helical molecules under an external electric field, which is perpendicular to the helix axis of the molecule. Our results reveal that the topological states could appear in single-helical molecule and double-stranded DNA in the presence of the perpendicular electric field. And these topological states guarantee adiabatic charge pumping across the helical molecules by rotating the electric field in the transverse plane and the pumped current at zero bias voltage is quantized. In addition, the quantized current constitutes multiple plateaus by scanning the Fermi energy as well as the bias voltage, and hold for various model parameters, since they are topologically protected against perturbations. These results could motivate further experimental and theoretical studies in the electron transport through helical molecules, and pave the way to detect topological states and quantized current in the biological systems.