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Details of Grant 

EPSRC Reference: EP/H016872/1
Title: Silicon-based Integrated Single-Spin Quantum Information Technology
Principal Investigator: MIZUTA, Professor H
Other Investigators:
Ashburn, Professor P Ferguson, Dr AJ TSUCHIYA, Dr Y
Chong, Professor HMH
Researcher Co-Investigators:
Project Partners:
Hitachi NTT Basic Research Laboratories
Department: Electronics and Computer Science
Organisation: University of Southampton
Scheme: Standard Research
Starts: 04 May 2010 Ends: 30 November 2013 Value (£): 1,009,703
EPSRC Research Topic Classifications:
Electronic Devices & Subsys. Magnetism/Magnetic Phenomena
Materials Processing
EPSRC Industrial Sector Classifications:
Related Grants:
Panel History:
Panel DatePanel NameOutcome
20 Nov 2009 ICT Prioritisation Panel (Nov 09) Announced
30 Sep 2009 ICT Prioritisation Panel (Oct 09) Deferred
Summary on Grant Application Form
The aim of this project is to realize a world-first Si-based integrated single-spin quantum bit (qubit) system on ultrathin silicon-on-insulator (SOI). We develop a precisely-controlled single-electron transfer technique to initialize truly single-electron spin (single-spin) states, micro electron spin resonance (micro-ESR) for single-spin manipulation, and a 'spin-to-charge' conversion technique for readout. These challenging technical requirements will be met by synergistically combining the expertise of the University of Southampton on cutting-edge silicon-based nanofabrication and single-electron devices, the University of Cambridge and the Hitachi Cambridge Laboratory on solid-state qubits and the associated low-temperature & RF measurements, and the NTT Basic Research Laboratories on single-electron / spin control technology.The first Si-based qubit was proposed by Kane using nuclear spins of phosphorous donor atoms in Si (Si:P qubits). This proposal attracted much interest due to the very long decoherence time of nuclear spins in Si. However, challenging bottom-up nanotechnologies, e.g. STM lithography, are required to control the number and position of P atoms embedded in silicon relative to surface control gates. Rather than using donors, which are atomic-like species, it is also possible to confine electrons in nano-fabricated structures known as quantum dots (QDs). An exquisite degree of control over single-electron spins (single-spins) has been demonstrated in QDs made from gallium arsenide. Unfortunately gallium arsenide is a nuclear spin rich environment leading to a rapid loss of coherence from electron spins. Recently, QDs capable of confining few electrons have also become feasible in silicon based materials, which have a low nuclear spin density, therefore providing a motivation for this research proposal. The recent appearance of isotopically pure Si materials (28Si 99.9%) also works in favour of Si-based systems by further increasing spin decoherence time. In order to develop the Si-based integrated single-spin qubit system, which has never been achieved, we fully exploit the unique set of state-of-the-art nanotechnologies brought together in our project team. Firstly, single-electron turnstile technology is adopted in order to prepare the well-defined initial single-spin states. Secondly, a high-speed charge detection technique is introduced using the radio-frequency single-electron-transistor (RF-SET). Thirdly, the detection of a single-spin state is realized based on the spin-to-charge conversion method. We propose a revolutionary SOI-based technology platform for integrated single-spin qubits, which features double single-spin turnstile devices (SSTDs) built as two parallel SOI-nanowires (SOINWs) with their edges interconnected by another short SOINW. The SSTDs are co-integrated with three other key components: (1) an in-plane single-electron electrometer formed adjacent to the edge of one of the SSTDs, (2) a micro-ESR device formed by using a metallic waveguide and placed near the SOINW interconnect, and (3) a nanomagnet which generates a magnetic field gradient across the single-spin qubits. By integrating all the building-blocks in a nanoscale footprint, we fully investigate initialization, selective manipulation and readout of the single-spin qubits for the first time on Si.
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Organisation Website: http://www.soton.ac.uk