A double quantum dot defined by top gates in a single crystalline InSb nanosheet

TL;DR

This paper demonstrates the fabrication and control of a double quantum dot in a single crystalline InSb nanosheet, highlighting its potential for quantum computing applications.

Contribution

It introduces a method to define and tune a double quantum dot in InSb nanosheets using top gates, supported by experimental and numerical analysis.

Findings

Successful creation of a tunable double quantum dot in InSb nanosheet

Charge states and inter-dot coupling can be efficiently controlled

Numerical simulations support experimental results

Abstract

We report on the transport study of a double quantum dot (DQD) device made from a freestanding, single crystalline InSb nanosheet. The freestanding nanosheet is grown by molecular beam epitaxy and the DQD is defined by top gate technique. Through the transport measurements, we demonstrate how a single quantum dot (QD) and a DQD can be defined in an InSb nanosheet by tuning voltages applied to the top gates. We also measure the charge stability diagrams of the DQD and show that the charge states and the inter-dot coupling between the two individual QDs in the DQD can be efficiently regulated by the top gates. Numerical simulations for the potential profile and charge density distribution in the DQD have been performed and the results support the experimental findings and provide a better understanding of fabrication and transport characteristics of the DQD in the InSb nanosheet. The achieved DQD in the two-dimensional InSb nanosheet possesses pronounced benefits in lateral scaling and can thus serve as a new building block for developments of quantum computation and quantum simulation technologies.