Alp Sipahigil (Advisor)

Superconducting qubits are a leading platform for scalable quantum computing. The transmon qubit, consisting of a Josephson junction (JJ) shunted by a coplanar capacitor, is widely adopted due to its robustness against charge noise. However, its scalability is limited by the large footprint and dielectric losses at material interfaces. The merged-element transmon (MET) was introduced to enable a more compact architecture, yet in current implementations, although the JJ area can be reduced to ~3 µm², the coplanar capacitor still occupies ~100 µm². Moreover, its planar geometry generates...

Silicon, a mature platform of modern semiconductor technology, is also emerging as a versatile host for quantum and nanoscale systems. In addition to its low-loss and low-noise properties, silicon can host defects that provide localized states with rich electronic and mechanical responses. In this project, we investigate defect-mediated electromechanical coupling in silicon, where lattice imperfections act as active media connecting electrical and vibrational degrees of freedom. By fabricating high-quality mechanical and superconducting resonators on silicon, we probe how defects influence...