Dr Ahsan Nazir

Dr Brendon Lovett

Dr Terry Rudolph

Quantum dynamics of energy transfer in optically driven nanosystems

The theory of energy transport has attracted much attention over recent years, not only due to its implications for foundational quantum mechanics but also the potential applications in quantum computing and solar harvesting technologies. Interest flared in this field when it was suggested that the solar harvesting organelles of plants utilise environmental noise and coherence to greatly improve both speed and efficiency of energy transport within their protein structures.  Although noise assisted transport is a somewhat counter-intuitive idea, work on the subject has identified that noise in these protein complexes suppresses destructive quantum interference and allows for new transport pathways to be. It has also been shown that the environment induces broadening of energy levels, therefore increasing the overlap of energy levels of neighbouring sites. This will in turn increase the coupling between neighbouring sites and hence aid the transfer of energy between them.

A standard approach to modelling dissipative quantum systems is to assume that the system-environment coupling is weak and acts as a perturbation to the system dynamics. Unfortunately, systems that exhibit efficient energy transport are often strongly coupled to their environment; as such, a standard weak coupling approach cannot be taken. My project is involved with developing techniques to go beyond the weak coupling regime and ultimately develop theories for describing efficient energy transport systems.