Simulation Software for Modelling Quantum Light Sources

Quantum photonics is an emergent field of technology promising to revolutionise science and day-to-day life alike. Amongst other benefits, it is anticipated that it will usher in ultra-secure communication, powerful super-fast computers and vastly increased data storage. These advancements are all based on the premise of developing single-photon sources: special sources of light characterised by emitting one photon at a time. Semiconductor quantum dots (QDs), consisting of nanometre-sized inclusions of one semiconductor within another, are atom-like systems emerging as attractive candidates for single-photon sources. However, they operate at very low temperatures requiring liquid helium cooling, which is a major drawback. This significant problem can be overcome by developing nitride QDs capable of emitting single photons at much higher temperatures. This project aims to test the application of Quantopticon's powerful simulation software in a context similar to that in which it might be sold, make it work faster and more effectively and provide it with a user-friendly interface. We will demonstrate that the software can have impact in a technologically important area. Our simulation tools will remove the need to carry out multiple, costly experiments, thus greatly accelerating and optimising the design and manufacture of nitride QD devices.

The UK Government injected £380 million into a new UK National Quantum Technologies Programme, transforming it into an area of high priority for economic development. The official vision of this programme is to 'create a coherent government, industry and academic quantum technology community that gives the UK a world-leading position in the emerging multi-billion-pound new quantum technology markets'. We believe that our project will help to reinforce the UK's reputation as a leading nation in technological innovation and boost its ranking in the Global Innovation Index (currently #3, after Switzerland and Sweden ) and generate substantial exports.

The proposed project is a necessary intermediate development phase on the path to the wholesale distribution of the Quantopticon code in the scientific and commercial arena. Optimising the performance and enhancing the features of the simulation would confer the crucial practicability required to transform our software into an important, easily navigatable tool for future technological advances and discoveries in the burgeoning quantum-photonic field. Once this is achieved, its intrinsic powerful capability to analyse and optimise advanced new quantum-photonic devices before fabrication would become truly exploitable on a large scale. By saving both time and financial resources, the code would accelerate the pace of innovation and free up funds for further creativity.

The overarching strength of the code resides in the fact that the aforementioned rigorous description of fundamental light-matter interactions can be translated into an extremely broad range of applications, encompassing quantum computing, telecommunications, metrology and sensing. This naturally makes it desirable for an unusually vast cohort of academia- and industry-affiliated researchers around the world.

We have estimated that using our code on a 42-month academic project evaluated at £1,520,000 would make a saving of £210,000 (14%) on experimental costs. Experiments of the sort typically consume up to 100 kWh of energy each. Running a simulation instead would use up only 1/40th of this energy. Since at least 52% of electricity comes from fossil fuel power stations, we could prevent 35 kg of CO2 being expelled into the atmosphere per experiment. Our project will therefore have a positive ecological impact.

Other key beneficiaries in society will be school students and the general public. We would like to foster social inclusion and promote exchange of ideas for non-scientists. We plan to conduct various public outreach activities to inspire curiosity about future quantum technologies and encourage public education and engagement with scientific research - for example at the Royal Society Summer Science Exhibition. In addition, we plan to volunteer at the Café Scientifique and Pint of Science events around the Oxford area. We plan to participate in the Soapbox Science initiative, raising the profile of women in science. We will disseminate our work via a Feature brief on phys.org and popular science blogs.