Simulation software for modelling nitride-based quantum light sources

Lead Research Organisation: University of Cambridge
Department Name: Materials Science & Metallurgy


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.

Planned Impact

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 lightmatter 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 and popular science blogs.


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Description We have demonstrated that by using micropillar based on distributed Bragg reflectors made from porous gallium nitride the purity of emission from a blue single photon source can be significantly enhanced.
Exploitation Route Our findings could be used to develop single photon emitters for free space or underwater quantum cryptography applications.
Sectors Digital/Communication/Information Technologies (including Software),Electronics,Security and Diplomacy

Description This is project is part of an InnovateUK project supporting a small company called Quantopticon. We have advised Quantopticon on commercialisation strategies, patenting and other aspects throughout, and our reserach has supported their development work.
First Year Of Impact 2018
Sector Digital/Communication/Information Technologies (including Software)
Impact Types Economic

Description Poro Technologies is an early stage spinout from the Cambridge Centre for Gallium Nitride focussed on porous GaN technologies for performance enhancement in LEDs 
Year Established 2018 
Impact Poro Technologies won the 2018 Cambridge Enterprise Postdoc Business Plan competition and is currently in discussion with venture capatalists about seed funding.
Description Communication using light - Hatchend School 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A workshop on the uses of light in communications, delviered to multiple classes in thee 14-16 age group and their teachers.
Year(s) Of Engagement Activity 2018
Description Little Light Sources With Big Ideas (#RobinSTEM) 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Schools
Results and Impact A short talk on quantum dots and single photon sources as part of the Robinson College Women in Science Festival, which I organise.
Year(s) Of Engagement Activity 2018
Description Secrets and Lights - Cafe Scientifique Bishops Stortford 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact A lecture on single photon sources and quantum cryptography
Year(s) Of Engagement Activity 2018