Quantum Technology Capital: Epitaxy Cluster Tool to Enable Next-Generation Quantum Dots for Quantum Technology Applications

This is a proposal for advanced crystal growth equipment to enable the UK to take a lead in important areas of Quantum Technologies. It will enable the growth of nanometre-scale semiconductor quantum dots with world-leading properties. These properties include emission limited only by fundamental properties of the dots unaffected by the surrounding environment, and ordered arrays of dots, critical to enable scale-up and to translate the much excellent science of quantum dots to highly competitive Quantum Technologies.
The Quantum Technology applications rely on purely quantum mechanical principles such as superposition, where a system can be in two states at the same time, and entanglement where an operation at one spatial location influences another remotely, without there being any direct connection between them. Quantum dots are extremely well suited to exploiting these quantum mechanical effects (sometimes termed 'Quantum 2'). The favourable properties of III-V semiconductor quantum dots include on-demand single and entangled photon emission, ready incorporation in cavities, very long coherence and compatibility with well-developed III-V semiconductor processing technology. III-V semiconductors are familiar in everyday life as the basis of light emitting diodes, internet data transmission, and laser disk storage to name just a few. Here we turn the favourable III-V properties to enable new applications in Quantum Technologies, including as sources for secure Quantum Cryptography, quantum relays for Quantum Communications, integrated entangled sources for Quantum Cryptography and sensing, and longer-term opportunities for memories and spin chains for Quantum Networks.
The crystal growth equipment, an Epitaxy Cluster Tool, is comprised of two principal chambers, one dedicated solely to the growth of highest quality quantum dots, and the second to the advanced processing of structured templates for growth of arrays of dots with pre-determined location, enabling the realisation of very high brightness sources of single photons and of arrays essential for scale-up. The two principal chambers will be connected together by an automated loading, transfer and analysis chamber, enabling high throughput of the system, and furthermore ensuring that only highest cleanliness wafers are transferred to the ultrahigh purity chamber. The Cluster Tool constitutes an integrated suite of growth, analysis and processing features. It will provide the UK with unique experimental infrastructure to take a leading position in the translation of quantum-dot-based science into Quantum Technologies.

This equipment proposal for a Molecular Beam Epitaxy Cluster Tool will Impact on many areas of Quantum Technologies, and on both Industry and Academia. It will enable exploitation of top-class quantum-dot-based Quantum Science, much of it originating in the UK, to new Quantum Technologies (QTs). Keeping in mind the long-term nature of much Quantum Technology, particularly when it involves equipment and materials development, dissemination and advertising of capabilities to industrial and academic collaborators will both be highly important and equally significant.
The Cluster Tool will be placed within the National Centre for III-V Technologies (co-I Heffernan Director, PI Skolnick Research Director). We will make full use of the highly-proven dissemination and customer-relations infrastructure of the Centre to advertise the Tool and its outputs to ensure maximum Impact. The Centre has a dedicated operations/business development manager, a modern and effective web-site and issues regular community updates of new developments to a very wide mailing list. These will all be employed to advertise the new capabilities. Furthermore it hosts the annual UK Semiconductors conference which attracts over 300 delegates to Sheffield each year, providing a further important dissemination route. Through these mechanisms we will ensure both industry and academia are kept fully informed on the timescales for commissioning, availability of the equipment, sample capabilities and achievements, and access mechanisms.
We will engage most actively with the Quantum Technology Hubs as a further major route to maximise Impact. The equipment will provide an important boost to the activities of the York Quantum Communications Hub. It will provide access to highest quality quantum dots, and the technological underpinning for incorporation in cavities and for scale up. The scale up enabled by site control is also a key requirement of the Oxford Quantum Networking Hub. We will keep the Hubs fully informed both by our direct, existing collaborations with their researchers, and by participation in their Open Days and User Forum events, where we will advertise our capabilities. The Hubs have an extensive list of industrial supporters. Our participation in their Open Days and direct links with their researchers will provide further effective dissemination to industry, beyond our own industrial collaborators. Furthermore, all our industry collaborators are committed to joint meetings, providing additional dissemination and exploitation routes.
As well as the main focus of Quantum Technology applications, the Cluster Tool has clear potential to lead to advances in epitaxial overgrowth, cleaning and passivation procedures, as well as development of high performance quantum dot lasers. These will be major topics in the regular meetings we have arranged with epitaxial growth and telecommunications component companies, as well as keeping them well-informed of Quantum Technology advances.
Dissemination to the wider public is important for all public funded Science and Technology. We have significant experience in this direction. This will be used to emphasise the importance of funding for equipment infrastructure and for research with more than 5 year horizons. We have generated three widely-viewed YouTube demonstrations (>27000 hits), will exhibit at the 2015 Royal Society Summer Science Exhibition, have given a BBC-radio interview on quantum physics, and have met with local MPs and MEPs. We will develop these contacts and expertise. Examples will include a new YouTube video on the Cluster Tool, emphasising its advanced technology in layman's terms, and by exhibiting at other festivals. New MPs will also be targeted. The PI has found MPs to be very receptive to approaches he has made in the last year. The focus in these meetings will be on infrastructure investment, and its long term societal impact, and of Quantum Technologies more generally.