Masters defense: Sofus Emil Mertz Budtz

Circuit Quantum Electrodynamics of a Two-Dimensional Electron Gas Based Gatemon Qubit Hosting a Quantum Dot

This thesis presents Circuit Quantum Electrodynamic (cQED) and transport measurements of a semiconducting gate tuneable transmon (gatemon) qubit with a gate-controlled quantum dot formed in the Josephson junction. The device is based in a two-dimensional electron gas (2DEG) heterostructure proximitised by superconducting aluminium. Qubit control circuitry compromised of superconducting transmission lines coupled to superconducting CPW resonators have been investigated and tuned specifically to the dot-gatemon, and on chip crossovers for improving the microwave environment on the chip have been designed, fabricated and measured.