A Reconfigurable Gate Architecture for Si/SiGe Quantum Dots

TL;DR

This paper presents a reconfigurable gate architecture for Si/SiGe quantum dots, enabling flexible quantum dot formation, charge sensing, and tunable coupling, with demonstrated control over electron occupation and valley splitting.

Contribution

Introduces a novel reconfigurable gate architecture that supports both single and double quantum dots with tunable parameters in Si/SiGe systems.

Findings

Achieved few-electron occupation in a single quantum dot with large charging energy.

Measured valley splittings between 35-70 microeV.

Demonstrated tunable tunnel coupling in a double quantum dot.

Abstract

We demonstrate a reconfigurable quantum dot gate architecture that incorporates two interchangeable transport channels. One channel is used to form quantum dots and the other is used for charge sensing. The quantum dot transport channel can support either a single or a double quantum dot. We demonstrate few-electron occupation in a single quantum dot and extract charging energies as large as 6.6 meV. Magnetospectroscopy is used to measure valley splittings in the range of 35-70 microeV. By energizing two additional gates we form a few-electron double quantum dot and demonstrate tunable tunnel coupling at the (1,0) to (0,1) interdot charge transition.