A high repetition rate semiconductor quantum dot light source (for the UK National Quantum Computing and Simulation Hub)
This research project is in competition for funding with one or more projects available across the EPSRC Doctoral Training Partnership (DTP). Usually the projects which receive the best applicants will be awarded the funding. Find out more information about the DTP and how to apply.
Start date: 1 October 2019
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 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.
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.
Project aims and methods
This project is suitable for a candidate with a degree in Physics or Engineering who has particular interest in optics, semiconductor and/or quantum information. It will make use of the facilities in 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.
The project is primarily experimental with the position holder taking responsibility for preparation of samples in the Institute cleanroom. This will involve handling wafers, lithography and etching: valuable and transferable skills in the UK semiconductor industry.
Optical characterisation will be carried out in the new state-of-the-art Quantum Technology lab using detectors sensitive to the arrival of single photons and ultrafast electronics to manipulate and measure devices. Practical lab skills will be gained including Labview programming, error analysis and data processing.