Quantum technologies for enhanced sensing and light absorption

Thesis

The counterintuitive properties of quantum mechanics have the potential to produce revolutionary new technology. The applications of these devices are both vital and diverse: the efficient generation of energy from light, sensing and measuring with exquisite precision, and information processing with unparalleled speed. In this thesis, I use the theory of open quantum systems to investigate quantum technologies for enhanced sensing and light absorption. In the first research chapter, we develop a new method for describing qubit dynamics in the Rabi model. We obtain a new expression for the ac Stark shift, which enables practical and precise qubit thermometry of an oscillator. In the second research chapter, we demonstrate that it is possible to invert the phenomenon of Dicke Superradiance using nanostructures and quantum control. This creates the possibility of a new class of quantum light absorption technologies with a super-linear scaling in the absorption rate. In the final research chapter, we investigate another means of enhancing light absorption. We show that phonon assisted transitions to ratchet states in rings allow absorbed excitions to be protected from reemission.

Authors: Higgins, K

• DOI: 10.5287/ora-mzqnrvjkn
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford