Conveyor-mode single-electron shuttling in Si/SiGe for a scalable quantum computing architecture

TL;DR

This paper demonstrates high-fidelity single-electron shuttling in Si/SiGe quantum channels using a conveyor-mode approach with minimal control signals, advancing scalable quantum computing architectures.

Contribution

It introduces a scalable conveyor-mode electron shuttling method in Si/SiGe quantum dots with only four control signals, achieving over 99.4% fidelity.

Findings

Achieved 99.42% single-electron shuttling fidelity.

Demonstrated smooth electron motion mapping potential disorder.

Shuttling device compatible with industrial fabrication processes.

Abstract

Small spin-qubit registers defined by single electrons confined in Si/SiGe quantum dots operate successfully and connecting these would permit scalable quantum computation. Shuttling the qubit carrying electrons between registers is a natural choice for high-fidelity coherent links provided the overhead of control signals stays moderate. Our proof-of-principle demonstrates shuttling of a single electron by a propagating wave-potential in an electrostatically defined 420 nm long Si/SiGe quantum-channel. This conveyor-mode shuttling approach requires independent from its length only four sinusoidal control signals. We discuss the tuning of the signal parameters, detect the smoothness of the electron motion enabling the mapping of potential disorder and observe a high single-electron shuttling fidelity of $99.42\pm0.02\,\%$ including a reversal of direction. Our shuttling device can be readily embedded in industrial fabrication of Si/SiGe qubit chips and paves the way to solving the signal-fanout problem for a fully scalable semiconductor quantum-computing architecture.