Nanoscale single-electron box with a floating lead for quantum sensing: modelling and device characterization

TL;DR

This paper models and characterizes a nanoscale single-electron box with a floating lead, demonstrating its potential for quantum sensing in silicon quantum dots through a novel theoretical approach and experimental validation.

Contribution

It introduces an extended multi-orbital Anderson impurity model for analyzing a nanoscale SEB with a floating lead, validated on silicon quantum dots, advancing charge sensing techniques.

Findings

The MOAIM accurately predicts electronic behavior of the SEB.

The metallic floating node effectively enables charge injection and detection.

Model limitations in higher-order effects are identified and discussed.

Abstract

We present an in-depth analysis of a single-electron box (SEB) biased through a floating node technique that is common in charge-coupled devices (CCDs). The device is analyzed and characterized in the context of single-electron charge-sensing techniques for integrated silicon quantum dots (QD). The unique aspect of our SEB design is the incorporation of a metallic floating node, strategically employed for sensing and precise injection of electrons into an electrostatically formed QD. To analyse the SEB, we propose an extended multi-orbital Anderson impurity model (MOAIM), adapted to our nanoscale SEB system, that is used to predict theoretically the behaviour of the SEB in the context of a charge-sensing application. The validation of the model and the sensing technique has been carried out on a QD fabricated in a fully depleted silicon on insulator (FDSOI) process on a 22-nm technological node. We demonstrate the MOAIM's efficacy in predicting the observed electronic behavior and elucidating the complex electron dynamics and correlations in the SEB. The results of our study reinforce the versatility and precision of the model in the realm of nanoelectronics and highlight the practical utility of the metallic floating node as a mechanism for charge injection and detection in integrated QDs. Finally, we identify the limitations of our model in capturing higher-order effects observed in our measurements and propose future outlooks to reconcile some of these discrepancies.