Novel characterisation of dopant-based qubits

TL;DR

This paper reviews electrical techniques for probing and understanding quantum states in dopant-based silicon qubits, crucial for advancing scalable quantum computing architectures.

Contribution

It provides a comprehensive overview of experimental and simulation methods used to characterize dopant qubits in silicon, highlighting recent advancements.

Findings

Electrical methods enable detailed quantum state analysis.

Atomistic simulations support device engineering.

Techniques accelerate development of silicon quantum technologies.

Abstract

Silicon is a leading qubit platform thanks to the exceptional coherence times that can be achieved and to the available commercial manufacturing platform for integration. Building scalable quantum processing architectures relies on accurate quantum state manipulation, which can only be achieved through a complete understanding of the underlying quantum state properties. This article reviews the electrical methods that have been developed to probe the quantum states encoded in individual and interacting atom qubits in silicon, from the pioneering single electron tunneling spectroscopy framework in nanoscale transistors, to radio frequency reflectometry to probe coherence properties and scanning tunneling microscopy to directly image the wave function at the atomic scale. Together with the development of atomistic simulations of realistic devices, these methods are today applied to other emerging dopant and optically addressable defect states to accelerate the engineering of quantum technologies in silicon.