Functional Nitride Nanocrystals for Quantum-Enhanced Technologies

This project will transform the current research field of advanced nanoscale materials through developing a new generation of doped nitride nanomaterials in which their quantum properties can be controlled. These materials will allow access to quantum properties at room-temperature enabling and supporting the development of quantum technologies (QTs) in the long term. They also have a number of immediate applications (generating quantum-enhanced technologies) including in ICT devices and as biomarkers.

In the 20th century the development of silicon-based electronics revolutionised the world, becoming the most pervasive technology behind modern-day life. In the 21st century the next revolutionary advance is predicted to come from the development of QTs. The most well-known quantum property is the dual particle-wavelike nature of electrons. This property is actually problematic in current technologies (e.g. transistors) which rely on electrons behaving as particles thus allowing them to be controlled using barriers. As these technologies are reduced in size these barriers start to fail as the wavelike properties of electrons come into play.

In QTs the wavelike nature of particles will form the essential basis on which functionality is built, rather than being a problem to be overcome. Additional quantum effects such as 'spin' and the use of quantum mechanisms that allow the interaction between particles (exchange fields) provide further key properties and phenomena which these technologies will exploit. To realise this, materials must be developed which allow these properties to be enhanced and controlled. This can be achieved by reducing the size of a material down to a length scale comparable to the wavelength of the electron within it. In practice this requires the use of nanomaterials. The most successful materials developed to date are semiconductor nanocrystals (NCs) whose properties may be controlled through simple changes to size and shape.

Furthermore early work has shown that by introducing magnetic dopants into these NCs, rich quantum behaviour can be observed including the ability to manipulate spin and magnetic properties using light. These are the only material systems to have shown such behaviour at room temperature, a significant requirement of any future QTs.

The project will directly address the EPSRC Physical Science Grand Challenges of Nanoscale Design of Functional Materials and Quantum Physics for New QTs through advanced development of these and new NC materials. Using doping we will control the NC optical, electronic and magnetic properties and determine strategies for enhancing them based on the detailed characterisation and modelling we will undertake. Furthermore, we will address the issue of uptake of NCs by industry and those working in biological applications through exclusive study of nitride based materials. These systems, which have yet to be studied in any detail, offer an alternative to more the commonly studied systems which contain heavy metals such as Cd and Pb.

Current understanding of the quantum behaviour exhibited in existing doped NC systems is incomplete, and the ability to predict and control properties remains limited. In our work we will therefore undertake a program of advanced characterisation ranging from fundamental studies of magnetic interactions in NC systems, using highly sensitive nanoSQUID devices, through to the incorporation and study of NCs within devices. Research into NCs within devices will provide the proof-of-principle required to guide and justify further developmental work that will form the basis of the future quantum-enhanced technologies.

Bringing together this leading team of interdisciplinary researchers and industrial partners to address the key challenges that face physical scientists today, this coherent and focused programme offers a unique opportunity to not only advance the field but place the UK in the lead with regard to QTs.

Who will benefit from the research?

The challenges we will address have been identified by EPSRC as being critical for enabling future advances in healthcare, sustainable materials, information handling, energy harvesting and storage and QTs. Such broad ranging impact will be of benefit to a wide range of stakeholders and end users outside of academia that include industry, funders of research and policy makers, government, healthcare institutions and those delivering it, education, the 'third sector' and the wider public, and the UK.

How will they benefit from this research?

Having initiated and been involved in defining the challenges we are addressing, funding bodies and stakeholders that they represent will benefit from the progress we make. The outcome of our research will inform and provide direct support for future research programme prioritisation relating to these challenges. As we develop new materials and technologies, other funders of research in different disciplinary areas will also benefit as the outcomes are translated into applications elsewhere (e.g. in bio/medical research for enhanced diagnostics).

Those developing future technologies and undertaking research and development in industry, evidenced by the presence of Sharp Laboratories of Europe, Hitachi Europe Ltd, and BASF as project partners alongside the National Physical Laboratory, will benefit from this project. Through our interactions with industry and their commercialisation of the materials and devices we will develop, there will be a wider benefit to the UK. We have intentionally designed into our research project the requirement to ensure that the materials we develop to meet the Grand Challenges are also suitable for commercial application through the consideration of the issues of stability, enhance capability and the need to ultimately move away from Cd and Pb-based systems. As a result, while the realisation of a commercial quantum technology is a longer-term aim, shorter term benefits exist through the provision of new materials and their use in biomarking and their incorporation into existing ICT technologies to provide significant improvements in performance (e.g. in photovoltaics, emitting devices, sensors). The PI leads Surrey's involvement in the UCL led Quantum Technology Hub proposal submitted to EPSRC and will actively engage with this community updating them on progress.

The area of our proposed work represents a unique example where the interplay of electronic, optical, magnetic and quantum effects can be directly demonstrated in an accessible way at room temperature. It is therefore ideally suited for providing a series of learning resources in which these properties may be introduced to students and their interactions explained. This can be applied from early school levels right through to undergraduate as the complexity is slowly revealed. We will therefore design and make available learning resources, working with educators, which will be made freely available for use by students and teachers.

The realization of the materials, effects, and devices envisaged within the programme will be transformational on the field in the short term setting the agenda internationally providing 'here and now' impact. On a longer timescale as quantum devices are realised and move into production the impact on quality of life, manufacturing, and the economy will be dramatic as reflected by the high level of interest in developing quantum technologies at highest levels of Government.

The UK will benefit from the research undertaken not only through the above contributions to policy, industry, education etc., but in being positioned as leading the development of next generation technologies via a world-leading research programme. This will translate into the wider benefits of increased competitiveness in research and development, which itself will attract further investment in this area and further talent to the UK.