Improving quality factors of superconducting resonator for the readout of gate-defined quantum dots

This project involves using a simplified architecture of quantum dot devices coupled to superconducting resonators on undoped GaAs. By sending light at a wavelength above the bandgap of GaAs, we create electron hole pairs. This allows us to remove numerous components commonly found in standard gate-defined quantum dot architectures. In addition, using a superconducting resonator enables non-destructive charge readouts and long-distance coupling between the quantum dots. However, the performance of the resonators is significantly impacted by dielectric losses, photogenerated charges and quasiparticles. This talk presents recent efforts to enhance fabrication methods for these resonators on substrates known for their high-performance microwave properties, such as Sapphire and high-resistivity Silicon, and assesses the effect of GaAs on the resonator's quality factors.