Masters defense: Kian Gao

Towards tantalum superconducting qubits with shadowed junction nanowires

Superconducting qubits are one of the most promising competitors owing to their scalability, fast gate time, and relatively mature fabrication technique. One way to gain control of the coupling among qubits is to tune the transition frequency of qubits. In this thesis, we propose a path of using tantalum-coated, shadowed in-situ grown S-Sm-S junction InAs nanowire as a gate tunable Josephson junction, and tantalum as capacitors and control lines to form gatemon qubits. The transport properties of the nanowires and the Q factors of the tantalum resonators are measured, which provide the prerequisite for creating tantalum gatemon qubits.