Cavity-assisted non-classical light generation

Quantum photonics is an emergent field of technology promising to revolutionise science and day-to- day life alike. Amongst other benefits, it is expected to usher in ultra-secure communication, powerful, super-fast computers, sensors with enhanced sensitivity and functionality and vastly increased data storage. These advancements are all based on the premise of developing non-classical light sources. In order to transition effectively to Quantum 2.0 devices that exploit quantum superposition and entanglement, it is essential that we advance our capability to generate and process non-classical states of light in scalable, integrated architectures. Producing number-states of light is a challenging problem that is central to the practical use of non- classical states of light. Solid-state quantum emitters, and in particular semiconductor quantum dots (QDs), provide an attractive quantum system that can be relatively easily controlled by incorporation into semiconductor structures, taking advantage of the matured semiconductor fabrication technologies. However, the inhomogeneity of these emitters in terms of emission wavelength and rate is a significant obstacle for constructing scalable quantum-photonic networks. For instance, the use of QDs is prohibitive for protocols that involve identical photons, such as linear optical quantum computing, or that involve the exchange of a photon between two qubits. Strikingly, this problem can be overcome by using adiabatic passage techniques, such as cavity-assisted stimulated Raman adiabatic passage (STIRAP) processes. The goal of this project is to investigate cavity-assisted schemes for the generation of high-quality single photons, enabled by combining experimental techniques with novel ground-breaking theoretical and computational modelling methods. This microscopic modelling naturally takes into account the precise position and size of the QD, as well as impacts such as birefringence, which are crucial for sophisticated protocols. In addition to enabling high-quality single- photon sources, this proposal paves the way for deterministic photon-photon gates, a key resource for efficient photonic quantum computation. This proposal is enabled by combining the complimentary leading expertise of three groups two theory groups providing unique and complementary expertise in the development of a revolutionary theoretical framework, and an experimental group performing crucial experiments to validate the new theory. Prof Müllers group has world-leading expertise in non-classical light generation with semiconductor QDs in the cavity-QED regime. Dr Slavchevas group has pioneered a new quantum stochastic theory for modelling light-matter interactions in quantum-photonic nanostructures and devices. Prof Jirauscheks group has profound expertise in statistical electromagnetics methods and highly-accurate numerical algorithms for solving the Maxwell-Bloch equations applied to the dynamics of optoelectronic devices.