Single-atom quantum phenomena in nanoscale semiconductor devices

Lead Research Organisation: University of Sheffield
Department Name: Physics and Astronomy

Abstract

Incremental advances in semiconductor technology of the past decades led to unprecedented miniaturization of optoelectronic integrated circuits, which now use billions of transistors, each containing only hundreds of atoms. However, these most sophisticated devices still rely on collective phenomena such as electric currents and light beams. These classical concepts are limited by atomic-scale effects and allow no further progress through miniaturization. Overcoming this bottleneck, would require a new generation of devices where atomic scale effects are no longer an obstacle but are used as a resource to build circuits through precise placement of individual atoms while exploiting quantum effects to boost information storage and processing capacity.

Recent innovations in semiconductor material science and technology offer new routes to atomic scale miniaturisation. This project relies on a new type of semiconductor quantum dots, which are tiny semiconductor crystals consisting of only a few thousand atoms. A comprehensive program of material development and experimental physics studies will seek to demonstrate quantum information storage and processing with nuclear magnetic states of individual atoms incorporated into a quantum dot. The broad goal of this proposal is to understand fundamental phenomena and develop material technologies that will stimulate and guide the transition from existing classical digital chips to future devices, which will eventually use every individual atom of a semiconductor crystal as a resource to build integrated circuits with Avogadro-scale number of elementary units and unprecedented information processing power and energy efficiency.

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/V048333/1 01/03/2021 31/01/2024 £200,848
EP/V048333/2 Transfer EP/V048333/1 01/02/2024 29/09/2024 £50,839
 
Description - Studied and explained the mechanism of nuclear spin decoherence induced by the electron spin qubit in a quantum dot [Nature Communications 13, 4048 (2022)].
- Collaborated on a Cambridge-led project, which demonstrated long electron spin qubit coherence times in gallium arsenide quantum dots [Nature Nanotechnology 10.1038/s41565-022-01282-2 (2023)].
- Studied and explained the mechanism of nuclear spin diffusion in low-strain quantum dots [Nature Communications https://doi.org/10.1038/s41467-023-38349-0 (2022)].
- Achieved record-high nuclear spin polarization in a semiconductor device [Nature Communications https://doi.org/10.1038/s41467-024-45364-2 (2023)].
- New type of quantum dot structures was developed, incorporating low-concentration atoms in to the quantum dot volume. Conducted initial studies of elastic strain in these structures using magnetic resonance.
Exploitation Route The findings from this project have stimulated two new research projects, including a QuantERA collaborative network, which aims to develop a solid-state quantum memory for applications in quantum communications. The outcomes would also be of use to academic communities working in the specific area of quantum dot semiconductor structures, and the broader field of solid state quantum science.
Sectors Digital/Communication/Information Technologies (including Software)

Other

 
Description Cambridge 
Organisation University of Cambridge
Department Department of Physics
Country United Kingdom 
Sector Academic/University 
PI Contribution We contributed to a joint project with results from magnetic resonance experiments.
Collaborator Contribution The team at Cambridge led the project.
Impact Research paper published: Nat. Nanotechnol. 18, 257-263 (2023). https://doi.org/10.1038/s41565-022-01282-2
Start Year 2021
 
Description JKU Linz Austria 
Organisation Johannes Kepler University of Linz
Country Austria 
Sector Academic/University 
PI Contribution We are studying spin phenomena in semiconductor quantum dots.
Collaborator Contribution Research group led by Prof Armando Rastelli have provide high quality semiconductor quantum dot devices
Impact Three papers published as a result of this collaboration.
Start Year 2015