Transport through multiply connected quantum wires

TL;DR

This paper investigates electron transport in coupled carbon nanotubes, revealing how conductance depends on gate voltages, temperature, and wire length, with mappings to quantum dot systems for theoretical insights.

Contribution

It provides a detailed analysis of conductance behavior in multiply connected quantum wires and maps the system to capacitively coupled quantum dots, offering new theoretical predictions.

Findings

Existence of equilibrium cross-conductance between wires

Dependence of conductance on temperature and wire length

Mapping to capacitively coupled quantum dot systems

Abstract

We study transport through multiply coupled carbon nano-tubes (quantum wires) and compute the conductances through the two wires as a function of the two gate voltages $g_1$ and $g_2$ controlling the chemical potential of the electrons in the two wires. We find that there is an {\it equilibrium} cross-conductance, and we obtain its dependence on the temperature and length of the wires. The effective action of the model for the wires in the strong coupling (equivalently Coulomb interaction) limit can also be mapped to a system of capacitively coupled quantum dots. We thus also obtain the conductances for identical and non-identical dots. These results can be experimentally tested.