Our Research
The focus of our work is in modelling open quantum systems. This means quantum systems that are interacting with the wider environment - in this sense all quantum systems are open to some degree. The system is typically something we can control and measure, and the environment is something that can only be described by thermodynamic (macroscopic) properties. It is not possible therefore to model that behaviour of the environment directly by solving the Schrödinger equation. However, we have been able to develop numerically exact methods, based on tensor networks, which enable us to calculate what the system is doing, even when it is interacting strongly with the environment.
We then use our methods for modelling open systems to design and, with experimental partners, try to realise architectures miniature electronics, quantum communication and quantum computing. We work on a variety of materials systems including semiconductor quantum dots, molecules and defects in crystals. We are particularly interested in optical control of electronic states in these materials, and we also look at how such materials behave when they are placed in an optical cavity.
Energy harvesting in photovoltaic cells relies on the creation and transport of electronic excitations in molecules or semiconductors. We also use open quantum system theory to understand how this process can be understood and optimized for efficient conversion of sunlight into electrical energy. Indeed, in recent work we have demonstrated super fast "charging" of a "quantum battery"
Collaborators
We collaborate widely. Our colleagues include Jonathan Keeling, Erik Gauger, John Morton, Ahsan Nazir, Tom Stace and Paul Eastham.