Thermal Symmetry Crossover and Universal Behaviors in Carbon Nanotube Dots

Motivated by recent experiments on electronic transport through a carbon nanotube dot, 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 (less than or similar to 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.