UCLA

In the evolving landscape of quantum computing, the emergence of quantum computers in the Noisy Intermediate Scale Quantum (NISQ) regime marks a significant stride. Superconducting qubits have garnered popularity in both academic and industrial groups. However, the journey towards achieving a large-scale, fully error-corrected quantum computer faces challenges. This thesis addresses some of these challenges within an academic setup. One prominent challenge with superconducting qubits is Purcell decay. This work aims to tackle the issue by delving into the implementation of on-chip Purcell filters with Transmon qubits. The overarching goal is to pave the way for further scalability by ensuring compatibility of these designs with scalability plans. The thesis also introduces novel architectures for superconducting qudit processors, focusing on their already presented implementation in 3D cavities. Efforts are directed towards transitioning these processors to a planar platform for enhanced scalability. The coupling of these processors to environment is explored using coplanar waveguides, with the system's physics governed by the principles of circuit quantum electrodynamics. Finally, the thesis also delves into the packaging of planar qubit devices, aiming to facilitate easy scalability. This platform enables interfacing the devices with control equipment, shielding from stray fields, and offers the essential thermal link to the dilution refrigerator where they are housed. Each section of the thesis presents results emphasizing potential areas for improvement and refinement of the systems.