Coherent electron transport in a helical nanotube

TL;DR

This paper investigates how the geometry of a helical nanotube influences quantum electron transport, revealing geometric effects like Fano resonances, conductance plateaus, and mode degeneracies through numerical solutions of the Schrödinger equation.

Contribution

It provides a detailed analysis of geometric effects on quantum transport in helical nanotubes, including the emergence of Fano resonances and conductance features, using a numerical approach.

Findings

Fano resonance as a geometric effect in conductance

New conductance plateaus observed

Transport properties differ from bent cylindrical surfaces

Abstract

The quantum dynamics of carriers bound to helical tube surfaces is investigated in a thin-layer quantization scheme. By numerically solving the open-boundary Schr$\ddot{\rm o}$dinger equation in curvilinear coordinates, geometric effect on the coherent transmission spectra is analysed in the case of single propagating mode as well as multimode. It is shown that, the coiling endows the helical nanotube with different transport properties from a bent cylindrical surface. Fano resonance appears as a purely geometric effect in the conductance, the corresponding energy of quasibound state is obviously influenced by the torsion and length of the nanotube. We also find new plateaus in the conductance. The transport of double-degenerate mode in this geometry is reminiscent of the Zeeman coupling between the magnetic field and spin angular momentum in quasi-one-dimensional structure.