Coupling a high impedance resonator to a Ge/Si nanowire

This thesis explores the development of quantum computing systems using Ge/Si core/shell nanowires, in particular coupled to high-impedance superconducting resonators. The work mainly addresses the challenges of scaling by improving qubit readout and remote coupling capabilities, but also by improving the coherence and speed of spin qubits. In particular, the fairly singular properties of Ge/Si nanowires, including a strong and tunable Rashba spin-orbit interaction, successfully coupled to high-impedance, magnetic field resilient, NbTiN superconducting resonators open up the possibility of strong spin-photon coupling in this system. In addition, the potential of using strontium titanate varactors for optimized readout through impedance matching is explored. Finally, a new operating regime that maximises coherence and speed in one-dimensional systems is shown and characterised. By providing insights into the design and optimisation of semiconductor-based spin qubit systems, this thesis contributes to ongoing efforts in the field of quantum computing.