Transport and current noise characteristics of a T-shape double quantum dot system

TL;DR

This paper analyzes the transport and noise properties of a T-shaped double quantum dot system with Coulomb interactions, revealing how these interactions influence conductance resonances and noise levels, relevant for quantum computing applications.

Contribution

It provides a theoretical analysis of Coulomb interaction effects on transport and noise in a T-shaped double quantum dot system using an equation of motion approach.

Findings

Presence of two Fano dips in conductance due to Coulomb interactions.

Noise levels are higher in slow detector regimes.

Coulomb interactions introduce additional resonances in the density of states.

Abstract

We consider the transport and the noise characteristics for the case of a T-shape double quantum dot system using the equation of motion method. Our theoretical results, obtained in an approximation equivalent to the Hartree-Fock approximation, account for non-zero on-site Coulomb interaction in both the detector and side dots. The existence of a non-zero Coulomb interaction implies an additional two resonances in the detector's dot density of states and thereafter affects the electronic transport properties of the system. The system's conductance presents two Fano dips as function of the energy of the localized electronic level in the side dot. The Fano dips in the system's conductance can be observed both for strong (fast detector) and weak coupling (slow detector) between the detector dot and the external electrodes. Due to stronger electronic correlations the noise characteristics in the case of a slow detector are much higher. This setup may be of interest for the practical realization of qubit states in quantum dots systems.