Linear conductance of an interacting carbon nanotube ring

TL;DR

This paper investigates the linear conductance of an interacting carbon nanotube ring under magnetic flux and gate voltage, revealing Coulomb blockade effects and flux periodicity variations due to electron interactions and quantum interference.

Contribution

It provides a theoretical analysis of how Coulomb interactions and quantum interference influence conductance resonances in a carbon nanotube ring.

Findings

Coulomb blockade effects suppress conductance resonances in certain flux regions.

The flux periodicity of conductance can vary, being smaller or larger than a flux quantum.

Quantum interference and electron interactions jointly determine the resonance pattern.

Abstract

Linear transport through a single-walled carbon nanotube ring (CNR), pierced by a magnetic field and capacitively coupled to a gate voltage source, is investigated starting from a model of interacting $p_z$-electrons. The dc-conductance, calculated in the limit of weak tunneling between the ring and the leads, displays a periodic resonance pattern determined by the interplay between Coulomb interactions and quantum interference phenomena. Coulomb blockade effects are manifested in the absence of resonances for any applied flux in some gate voltage regions; the periodicity as a function of the applied flux can be smaller or larger than a flux quantum depending on the nanotube band mismatch.