Creating, detecting and exploiting quantum states of light

Lead Research Organisation: Heriot-Watt University


In the last ten to fifteen years there has been a world-wide expansion in investigation into quantum states of light. Much of the expansion in this subject area has been stimulated by the emergence of quantum cryptography or quantum key distribution (QKD) / first proposed in 1984 - which offers unconditionally secure information sharing guaranteed by quantum-mechanical laws. Whilst QKD still remains a fertile subject of exciting laboratory and field research, experimental progress in free-space and optical fibre transmission media have taken quantum cryptography to the fringes of commercial exploitation and real-world application. Concurrently, a number of other developments in quantum information research have also been highly significant, such as quantum computing algorithms that, if realised, would make today's public-key based data security system obsolete. The building blocks, or quantum components, of these quantum-based systems require considerable research effort and this is the main subject matter of this proposal. Significantly and perhaps in a more short-term manner, a number of these components will be utilised in other applications outside the quantum information processing sphere; these applications include including low-light level communications (eg as proposed in the NASA Mars Communications Programme), in remote sensing, low light level imaging, quantum or ghost imaging, and quantum-based metrology.

This Platform Grant application from the Heriot-Watt group centres on leading edge research into the creation, detection and exploitation of the quantum states of light. This project will be used to make strategic decisions regarding research in these fast-moving fields. At the time of application, several exciting projects have been highlighted for investigation, although these projects are not meant to represent a comprehensive and exclusive list of research topics. Some areas worth immediate investigation include novel solid-state indistinguishable single photon sources, photon-number resolving detectors, optical generation of spin entanglement, few photon non-linearities with 'waveguide-QED', and large alphabet QKD. Whilst this grant will not provide the full resources for long-term investigations into all these areas, this project will permit rapid start-up and allow the group to collaborate more effectively with other groups, including overseas researchers.

Planned Impact

In the last 15 years, quantum information research has led to the discovery of several new paradigms for information processing and communication. These developments include quantum cryptography schemes that offer unconditionally secure information transport guaranteed by quantum-mechanical laws and quantum processors that, if realised, would make today's public-key based data security system obsolete. Evidently these potentially disruptive security technologies are likely to be of enormous strategic and economic value in the future. Consequently, quantum information technologies are predicted to be a major driver of technological progress and economic growth in the 21st century [1]. For example, the market for quantum cryptography alone is predicted to reach $842M US by 2015 [2] and all quantum information to be worth $26 Billion from 2015-2020 [3]. It is clear that the subject matter of this Platform Grant renewal will remain highly relevant, and that interest in the subject will not be confined to research labs, but will extend to the business community and general public alike. We are committed to gaining maximum impact from this Platform Grant project via a number of avenues, including engaging high-technology industry and UK and overseas standards laboratories.

Throughout this project, we will engage with high-tech industry at every opportunity. Our project partners are SELEX Galileo (Edinburgh), National Physical Laboratory, and National Institute of Standards and Technology (USA) who will provide support in terms of laboratory access, guidance on research strategy and access to their own industrial partners. We will engage Heriot-Watt University Research and Enterprise Services for advice on intellectual property protection and commercial exploitation, as progress dictates.

[1] D Corker, et al "Commercial Prospects for Quantum Information Processing" EPSRC QIP IRC December 2005
[2] Global Industry Analysts, Inc. Quantum Cryptography Strategic Business Report MCP-812 July 2009
Description The Platform Grant "Creating, detecting and exploiting quantum states of light" has provided flexible funding in a rapidly expanding research area. Aided by the flexibility of the Platform Grant funding we have been able to ensure that post-docs were continuously employed between the timeframes of multiple grants and also further enabled multiple research groups to further integrate their research teams to create new synergies and ideas. Furthermore, the Platform Grant has contributed to developing the careers of several early career researchers who are currently transitioning into positions with growing independence. During the Platform Grant, the EPSRC QT Hubs were formed, and the Platform Grant was particularly useful in flexibly funding a number of PDRAs as the new funding encountered delays. The Platform Grant helped by keeping an excellent team, together and allowed the Heriot-Watt part of the Hubs to have a running start in the National Quantum Technology Programme.
A number of Research highlights were made as a direct result of Platform Grant funding:
• We demonstrated three-dimensional imaging using particles of light, or single-photons, in a range of extreme conditions: (i) at record distances of 10km; (ii) to see through camouflage in an outdoor environment; (iii) in highly scattering underwater conditions; and (iv) to reconstruct full colour images with very few photons.
• We demonstrated the first practical quantum digital signatures experiment in a laboratory and later in an installed optical fibre network. This allows verifiably secure transmission of messages through a network with a number of receivers, for the first time.
• To develop a whole new semiconductor detector - made from germanium on silicon - capable of measuring single-photons at wavelength compatible with optical fibre transmission
• Developed semiconductor devices which emit identical particles of light (photons) on-demand (e.g. with the touch of a button). These single photons underpin a range of emerging quantum technologies
• We have discovered the limiting mechanisms for electron spin coherence and its impact on generating coherent photons in a single semiconductor quantum dot (often called an artificial atom). This enables us to engineer the quantum states to mitigate the effects of these mechanisms for future quantum technologies.
• We have discovered and further engineered approaches to create artificial atoms, which can trap single particles of charge (electrons) and generate single particles of light (photons), in so called two-dimensional semiconductors which are only 1 layer of atoms thick.
• Demonstrated epitaxial lift-off of II-VI semiconductors for the first time, allowing integration of II-VI semiconductors on other platforms.
Many of these highlights have been used in the National Quantum Technology Programme by our group and our collaborators. The Platform Grant proved pivotal in securing international leading work in quantum technology.
Exploitation Route A number of different areas will be affected by these findings as quantum technology starts to be used in various industries. Since the grant ended, we have been approached by the defence sector, offshore exploration, telecommunications research for possible collaborative work.
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Security and Diplomacy

Description This led the way to involvement in the EPSRC Quantum Technology Hub programme (specifically QuantIC and QuComms) which started in December 2014. This grant also provided the groundwork for Professor Gerald Buller's EPSRC Established Career Fellowship and also that of Professor Brian Gerardot's Royal Academy of Engineering Chair in Emerging Technologies. In terms of non-academic outputs, this grant also provided some of the foundation work that later was used in industry led Innovate UK projects, AquaSec (Nov 2018 - Aug 2021), SPIDAR (Feb 2021 - Sep 2023 ), QuEOD (Sep 2020 - May 2023) and USPIS (Apr 2022 - Mar 2027). These collaborations included industry partners such as Toshiba, BT, BP, Leonardo, Thales, Sonardyne, Jaguar Land Rover, Network Rail and others.
First Year Of Impact 2014
Sector Aerospace, Defence and Marine,Chemicals,Digital/Communication/Information Technologies (including Software),Electronics,Energy,Environment,Manufacturing, including Industrial Biotechology,Security and Diplomacy,Transport
Impact Types Societal,Economic,Policy & public services

Description DSTL
Amount £159,896 (GBP)
Organisation Defence Science & Technology Laboratory (DSTL) 
Sector Public
Country United Kingdom
Start 06/2015 
End 07/2019
Description EPSRC
Amount £581,515 (GBP)
Funding ID EP/P029892/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 09/2017 
End 03/2021
Description EPSRC Quantum Technology Fellowship - Gerald Buller
Amount £1,418,014 (GBP)
Funding ID EP/N003446/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 06/2015 
End 06/2020
Description ERC Consolidator Grant - Brian Gerardot
Amount € 2,000,000 (EUR)
Organisation European Research Council (ERC) 
Sector Public
Country Belgium
Start 01/2018 
End 12/2022
Description MoD Seeing Through Clouds
Amount £412,232 (GBP)
Funding ID DSTLX1000108233 
Organisation Defence Science & Technology Laboratory (DSTL) 
Sector Public
Country United Kingdom
Start 05/2016 
End 06/2018
Description Royal Academy of Engineering Chair in Emerging Technology - Brian Gerardot
Amount £1,300,000 (GBP)
Organisation Royal Academy of Engineering 
Sector Charity/Non Profit
Country United Kingdom
Start 03/2018 
End 02/2028
Description Standard Research - Applications of Epitaxial lift off technology for II-VI semiconductors
Amount £388,038 (GBP)
Funding ID EP/L025396/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 08/2014 
End 05/2018
Description UK Quantum Technology Hub for Quantum Communications Technologies
Amount £24,093,966 (GBP)
Funding ID EP/M013472/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 12/2014 
End 11/2019
Description UK Quantum Technology Hub in Quantum Enhanced Imaging
Amount £23,061,154 (GBP)
Funding ID EP/M01326X/1 
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Public
Country United Kingdom
Start 12/2014 
End 11/2019
Title Photon-sparse microscopy: Visible light imaging using infrared illumination 
Type Of Material Database/Collection of data 
Year Produced 2015 
Provided To Others? Yes  
Description A single photon avalanche diode (SPAD) device is presented. The SPAD device comprising: a Si-based avalanche layer formed over an n-type semiconductor contact layer; a p-type charge sheet layer formed in or on the avalanche layer, the p-type charge sheet layer having an in-plane width; a Ge-based absorber layer, formed over the charge sheet layer and/or the avalanche layer, and overlapping the charge sheet layer, the Ge-based absorber layer having an in-plane width; wherein, at least in one in-plane direction, the in-plane width of the Ge-based absorber layer is greater than the in-plane width of the p-type charge sheet layer. 
IP Reference WO 2020/053564 A1 
Protection Patent application published
Year Protection Granted 2020
Licensed No
Impact Patent currently being pursued in a number of jurisdictions.