Inter-valley scattering induced by Coulomb interaction and disorder in carbon-nanotube quantum dots

TL;DR

This paper develops a theoretical model for inter-valley Coulomb scattering in carbon nanotube quantum dots, considering effects like curvature, chirality, and disorder, revealing measurable energy splittings.

Contribution

It introduces a comprehensive theory that includes Coulomb interaction, spin-orbit coupling, and disorder effects in inter-valley scattering for carbon nanotube quantum dots.

Findings

Energy level splittings are nearly independent of chiral angle.

Splittings are smaller than spin-orbit effects but still measurable.

The theory predicts observable inter-valley scattering effects.

Abstract

We develop a theory of inter-valley Coulomb scattering in semiconducting carbon-nanotube quantum dots, taking into account the effects of curvature and chirality. Starting from the effective-mass description of single-particle states, we study the two-electron system by fully including Coulomb interaction, spin-orbit coupling, and short-range disorder. We find that the energy level splittings associated with inter-valley scattering are nearly independent of the chiral angle and, while smaller than those due to spin-orbit interaction, large enough to be measurable.