Defective transport properties of three-terminal carbon nanotube junctions

TL;DR

This paper studies how nonhexagonal defects in three-terminal carbon nanotube junctions affect quantum transport, revealing Fano resonances and significant conductance variations due to localized states.

Contribution

It demonstrates the influence of defective arrangements on transport properties and identifies Fano resonances arising from interference effects in these junctions.

Findings

Fano resonances emerge from interference between localized and extended states.

Defective arrangements can cause conductance modulations up to 75%.

Localized states act as pinning centers affecting quantum transport.

Abstract

We investigate the transport properties of three terminal carbon based nanojunctions within the scattering matrix approach. The stability of such junctions is subordinated to the presence of nonhexagonal arrangements in the molecular network. Such "defective" arrangements do influence the resulting quantum transport observables, as a consequence of the possibility of acting as pinning centers of the correspondent wavefunction. By investigating a fairly wide class of junctions we have found regular mutual dependencies between such localized states at the carbon network and a strikingly behavior of the conductance. In particular, we have shown that Fano resonances emerge as a natural result of the interference between defective states and the extended continuum background. As a consequence, the currents through the junctions hitting these resonant states might experience variations on a relevant scale with current modulations of up to 75%.