Thermal Symmetry Crossover and Universal Behaviors in Carbon Nanotube Dots

TL;DR

This paper explores how slight asymmetries in Coulomb interactions affect the conductance behavior of carbon nanotube quantum dots at finite temperatures, revealing a thermal symmetry crossover.

Contribution

It introduces the concept of thermal symmetry crossover in carbon nanotube dots and analyzes how small Coulomb asymmetries influence conductance profiles.

Findings

Small Coulomb asymmetry (~10%) significantly deforms conductance profiles.

Thermal symmetry crossover is characterized and explained.

Conductance behavior is highly sensitive to intra- and inter-orbital Coulomb interactions.

Abstract

Motivated by recent experiments on electronic transport through a carbon nanotube, we investigate the role of the intra- and inter-orbital Coulomb interactions on the temperature evolution of the conductance. It is shown that small amount (~10%) of asymmetry between these Coulomb repulsions substantially deforms the conductance profile at finite temperature, particularly around half-filling. The nature of such thermal symmetry crossover is elucidated.