Electromagnetically induced transparency with localized impurity electron spins in a semiconductor

This PhD project contributes to a research field that aims to understand and extend the limits of how well quantum states of matter and optical fields can be prepared, controlled and detected. Central to this PhD research was the question whether an effect known as Electromagnetically Induced Transparency (EIT) can be realized with electron spins in a semiconductor. EIT forms the basis of many quantum-optical control schemes that use long-lived spin states. EIT can occur when two optical fields each drive a transition from one of two spin states to the same excited state. The application scenario is that information can be swapped between optical signal pulses and a memory function in matter, in a way that allows for processing the information in a quantum mechanical manner. Such quantum mechanical processing of information may lead to safer communication in optical fiber networks. A key result of this PhD project is the successful demonstration of EIT in the semiconductor material GaAs. The project used the spin of electrons that are located at donor atoms in the material. The thesis also reports on experiments that provide the foundation for this result, as well as on experiments that explore the limitations and possible improvements of the EIT effect in this material. This includes spectroscopy of the optical transitions of the donor atoms, studies of interactions between the spin of the donor electron and its semiconductor environment, and the design and development of unique instrumentation that was required for the research