Developing and scaling of a quantum computing test bed

• Main Author: Nguyen, Hoang Long
• Other Authors: Rainer Helmut Dumke
• Format: Thesis-Doctor of Philosophy
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Science::Physics::Atomic physics::Solid state physics
• Online Access: https://hdl.handle.net/10356/173357
• Institution: Nanyang Technological University

Superconducting transmon qubits have seen significant progress in the last five years. By optimizing and exploring different fabrication process and superconducting material, transmon lifetime is more than 100 us with single-qubit gate and two-qubit gate fidelity is higher than to 99.8%. This thesis reports work to realize a transmon qubit fabrication process and experiment test bed. The experiment stage at the mixing chamber of the dilution fridge is designed and the microwave setup for qubit control and characterization is demonstrated. The qubit fabrication recipe using aluminum and Al/AlOx/Al junction is developed and measured. The qubit lifetime reach an average of 10 us and single-qubit gate fidelity is F = 99.883 +- 0.007%. While the parameters are moderate compared to the state of the art, this system is a good stepping stone to explore qubit scaling and optimization.