Theory of Quantum Light Sources: how can we make coherent single photons in solid state systems?
Supervisor: Dr Brendon Lovett (St Andrews)
The generation of indistinguishable single photons on demand is a key requirement for many kinds of future quantum technologies, such as secure communication and optical quantum computing . Being able to make coherent quantum light sources in solid state systems would enable us to create on-chip photonic circuits that would enable this technology. It is therefore of the utmost importance to understand what effect a solid state environment has on the fidelity of emitted photons. In this project, you will exploit and developing a groundbreaking new technique our group has created for simulating open quantum systems . Based on a combination of Feynman's path integrals [3,4] and matrix product states , it has already enabled calculations impossible by more traditional means. You will study how the technique might be used to calculate the photon correlation functions that characterise a single photon source, in the presence of a strongly-coupled environment of vibrational modes of the crystal. You will go on to study how a photonic cavity might be used to improve the performance of such a device.  I. Aharonovich. D. Englund and Milos Toth, Nature Photonics 10 631 (2016)  A. Strathearn, P. Kirton, D. Kilda, J. Keeling, and B. W. Lovett. , Nature Communications 9 3322 (2018)  R. P. Feynman, and F. L. Vernon, Jr., Ann. Phys. 24 118 (1963)  N. Makri and D. E. Makarov. The Journal of Chemical Physics J. Chem. Phys. 102 4600 (1995)  R. Orús, Annals of Physics 349 117 (2014)