Transport through a quantum dot with two parallel Luttinger liquid leads

TL;DR

This paper investigates electron transport through a quantum dot connected to two parallel Luttinger liquid leads, revealing how Coulomb interactions and dot positioning influence conductance and current behavior.

Contribution

It provides an exact analysis of inter-lead Coulomb interactions in a quantum dot system with parallel Luttinger liquids, highlighting the impact of geometry on transport properties.

Findings

Charge fluctuation correlations can enhance current at Coulomb-blockade edges.

Symmetry and separation affect conductance, causing suppression or enhancement.

Negative differential conductance can occur due to inter-lead interactions.

Abstract

We study transport through a quantum dot side-coupled to two parallel Luttinger liquid leads in the presence of a Coulombic dot-lead interaction. This geometry enables an exact treatment of the inter-lead Coulomb interactions. We find that for dots symmetrically disposed between the two leads the correlation of charge fluctuations between the two leads can lead to an enhancement of the current at the Coulomb-blockade edge and even to a negative differential conductance. Moving the dot off center or separating the wires further converts the enhancement to a suppression.