Expanded quantum science applications for single atoms in silicon

The control and measurement of the quantum state of single phosphorus atoms in silicon has opened up vast newavenues for exploration of quantum effects. The work outlined in this thesis describes the development of several ofthese avenues, extending the applications of the system for quantum science. The electron and nuclear states of thephosphorus donor have been utilised as a quantum memory, experimental means have been developed to opticallyaddress these quantum states, and experiments were developed to probe the nature of causality and time-symmetryin quantum systems.