Defect-induced multicomponent electron scattering in single-walled carbon nanotubes

TL;DR

This paper combines theoretical modeling and experimental STM data to analyze how defects in single-walled carbon nanotubes influence electron scattering, revealing detailed scattering processes related to tube chirality.

Contribution

It develops a formalism for quantum transport in defected nanotubes with contacts and STM tips, linking theoretical predictions with experimental observations.

Findings

Reproduces particle-in-a-box-like states observed experimentally

Identifies inter- and intra-valley scattering signatures depending on chirality

Provides a detailed comparison between theory and STM measurements

Abstract

We present a detailed comparison between theoretical predictions on electron scattering processes in metallic single-walled carbon nanotubes with defects and experimental data obtained by scanning tunneling spectroscopy of Ar$^+$ irradiated nanotubes. To this purpose we first develop a formalism for studying quantum transport properties of defected nanotubes in presence of source and drain contacts and an STM tip. The formalism is based on a field theoretical approach describing low-energy electrons. We account for the lack of translational invariance induced by defects within the so called extended kp approximation. The theoretical model reproduces the features of the particle-in-a-box-like states observed experimentally. Further, the comparison between theoretical and experimental Fourier-transformed local density of state maps yields clear signatures for inter- and intra-valley electron scattering processes depending on the tube chirality.