Postgraduate research opportunities Mapping quantum electronic properties on photonic states

The PhD student will investigate theoretical methods for mapping quantum electronic states in a semiconductor onto emitted quantum photonic states. The National Physical Laboratory (NPL) has developed precise metrology devices, single-electron sources, with metrologically accurate control of electron emission with less than 10^-7 error rate and a timing accuracy down to one picosecond. These can be adapted to achieve accurate control of electron injection for photon emission through hole recombination. Quantum state transfer, mapping the electron’s quantum state (e.g. spin, spatial wavefunction) onto the emitted photon, would be valuable in realising quantum networks for photonic sources or transduction between quantum processors and communication channels. Presently, it is unknown whether such coherent mapping is possible in realistic experimental conditions present in recombination of injected electrons, hence it is first necessary to perform theoretical investigations. The objective of the project is to identify the most promising methods of quantum state transfer and these results will inform experimental efforts at NPL such as new device architectures, modes of operation, and characterisation techniques. Quantum networking is a strategic priority of EPSRC and within the UK National Quantum Technology Programme (UK NQTP).

NPL will guide the PhD project by providing the knowledge and expertise in single-electron devices for the student to explore the parameter space achievable in experiments. It is important that the parameter space investigated matches realistic cases in terms of the material, dimensions, and environment (temperature etc) of the experimental device and cryogenic optical measurement setup, so that the findings are relevant and applicable to NPL’s experiments. NPL will transfer the relevant knowledge to the student and their academic supervisors through regular meetings and occasional visits by the NPL supervisor to the university. NPL will also arrange yearly short visits (at least three months in total over the duration of PhD) for the student to work on relevant experiments so that they gain the knowledge of NPL’s experimental activities and understand the experimental constraints.

This project is based on a novel concept of photon emission by single electrons travelling in an electron waveguide (quantum Hall edge states) in a semiconductor substrate. Very little information is available in the current literature on such processes. This project will develop skills for understanding and modelling such coherent electron-photon phenomena. The student’s successful outputs will be their original work, and scientifically ambitious and challenging.

Further information

This is a 4-year EPSRC funded iCASE studentship held by NPL in collaboration with the University of Strathclyde. The student will primarily be based at Strathclyde (Glasgow) with visits to NPL (London). The PhD will be conducted in the Computational Nonlinear and Quantum Optics (CNQO) group in Optics Division, Department of Physics, University of Strathclyde. Strathclyde is the only institution to be a member of all 4 Quantum Technology Hubs in both phases of the UK National Quantum Technology Programme. The project will be as part of the QT Hubs in Quantum Communications (QCH) and Quantum Imaging (QuantIC).

The student’s work at NPL will be performed in the Quantum Electrical Metrology Group, funded by NPL’s Quantum Programme.