Impurity effects on Fabry-Perot physics of ballistic carbon nanotubes

TL;DR

This paper develops a theoretical model to understand how impurities affect the Fabry-Perot interference patterns in ballistic carbon nanotubes, enabling impurity detection and positioning through conductance measurements.

Contribution

It introduces a scattering field theory model that links impurity presence and location to conductance patterns in nanotubes, advancing understanding of impurity effects.

Findings

Impurities alter Fabry-Perot conductance patterns in nanotubes.

Conductance measurements can identify and locate impurities.

Impurities' activity depends on substrate interaction via back-gate.

Abstract

We present a theoretical model accounting for the anomalous Fabry-Perot pattern observed in the ballistic conductance of a single-wall carbon nanotubes. Using the scattering field theory, it is shown that the presence of a limited number of impurities along the nanotube can be identified by a measurement of the conductance and their position determined. Impurities can be made active or silent depending on the interaction with the substrate via the back-gate. The conceptual steps for designing a bio-molecules detector are briefly discussed.