Single-electron charging and detection in a laterally-coupled quantum dot circuit in the few-electron regime

TL;DR

This paper analyzes the charging and detection of the first few electrons in a laterally-coupled GaAs/AlGaAs quantum dot circuit using numerical simulations, matching experimental stability diagrams.

Contribution

It provides a detailed numerical analysis of electron charging in a coupled quantum dot circuit, including stability diagrams that agree with experiments.

Findings

Numerical solutions of the Kohn-Sham equations reveal electronic states and spectra.

The stability diagram matches experimental data.

Insights into electron confinement and detection in quantum dot circuits.

Abstract

We provide a physical analysis of the charging and detection of the first few electrons in a laterally-coupled GaAs/AlGaAs quantum dot (LCQD) circuit with integrated quantum point contact (QPC) read-out. Our analysis is based on the numerical solution of the Kohn-Sham equation incorporated into a three-dimensional self-consistent scheme for simulating the quantum device. Electronic states and eigenenergy spectra reflecting the particular LCQD confinement shape are obtained as a function of external gate voltages. We also derive the stability diagram for the first few electrons in the device, and obtain excellent agreement with experimental data.