Effect of quasi-bound states on coherent electron transport in twisted nanowires

TL;DR

This paper investigates how twisting nanowires influences electron transport by analyzing quantum transmission spectra, revealing the role of quasi-bound states and resonances in modulating conductance.

Contribution

It provides a detailed numerical analysis of the effects of twist on quasi-bound states and their impact on electron transmission in twisted nanowires.

Findings

Twist increases the energy of quasi-bound states.

Localized states cause Breit-Wigner and Fano resonances.

Twist can mitigate conductance reduction by shifting localized levels.

Abstract

Quantum transmission spectra of a twisted electron waveguide expose the coupling between traveling and quasi-bound states. Through a direct numerical solution of the open-boundary Schr\"odinger equation we single out the effects of the twist and show how the presence of a localized state leads to a Breit-Wigner or a Fano resonance in the transmission. We also find that the energy of quasi-bound states is increased by the twist, in spite of the constant section area along the waveguide. While the mixing of different transmission channels is expected to reduce the conductance, the shift of localized levels into the traveling-states energy range can reduce their detrimental effects on coherent transport.