Photons are ideal carriers of quantum information, being fast, cheap and easy to encode with quantum-information carried in their polarisation, phase, time or path degrees of freedom. The challenge in developing useful optical quantum algorithms is to scale to larger photon numbers when detection efficiencies are not perfect. Indium-Gallium-Arsenide semiconductor quantum dots in high quality microcavities are among the most efficient photon sources known  and can deliver photons one-by-one. Recent breakthroughs have demonstrated resonant pi-pulse excitation of these light sources  leading to unprecedented figures of merit.
This PhD project will build on this technology to develop high efficiency and high purity semiconductor quantum light sources for collaborators in the UK’s National Quantum Computing and Simulation Hub . Fabricated devices will feed quantum circuits and networks being built in partner universities of Bristol, Bath and Imperial. The focus of the project will be on increasing the efficiency and repetition rate of the single photon source to make higher photon number experiments possible, ultimately delivering an optical quantum simulation that outperforms a classical computer.
This project would be suitable for a candidate with a degree in Physics or Engineering who has particular interest in optics, semiconductor and/or quantum information. It will use of the facilities of the Institute for Compound Semiconductors, including a new state-of-the-art quantum optics lab, a refurbished cleanroom and Ser Cymru epitaxy facilities. In year 1 of this project you will design and test microcavities. In Year 2 you will optimise the photon collection apparatus to be portable, stable and efficient. In year 3 you will collaborate with partner institutions in the National Quantum Computing and Simulation Hub to test your source in their networks and photonic circuits. Throughout the project you will attend regular meetings of the Hub consortium providing excellent access to this world-leading activity.
For more information contact Dr Anthony Bennett at [email protected]
, 02920 875 404, Room S0.06, Institute for Compound Semiconductors, School of Engineering, Cardiff University.
 “Near-optimal single-photon sources in the solid state”, N. Somachi et al, Nature Photonics 10, 340–345 (2016)
 “Cavity-enhanced coherent light scattering from a quantum dot” A J. Bennett et al, Science Advances 2016: e1501256
You should have obtained, or be about to obtain, a First or Upper Second Class UK Honours degree, or the equivalent qualifications gained outside the UK.
Applicants with a Lower Second Class degree will be considered if they also have a master’s degree. Applicants with a minimum Upper Second Class degree and significant relevant non-academic experience are encouraged to apply.
Full awards, including the Tuition fee and maintenance stipend (Approx. £14,777 in 2018/19), are open to UK Nationals and EU students who can satisfy UK residency requirements. To be eligible for the full award, EU Nationals must have been in the UK for at least 3 years prior to the start of the course for which they are seeking funding, including for the purposes of full-time education.
Applications should be made online at: https://www.cardiff.ac.uk/study/postgraduate/applying/how-to-apply/online-application-service.
Please note the following when completing your online application:
The Programme name is Doctor of Philosophy in Engineering with an October 2019 start date.
In the "Research proposal and Funding" section of your application, please specify the project title, supervisors of the project and copy the project description in the text box provided.
Please select “No, I am not self-funding my research” when asked whether you are self-funding your research.
Please quote “project ID” when asked "Please provide the name of the funding you are applying for".