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...

Color centers in solid-state materials are promising candidates as single-photon emitters for quantum information technologies. For color centers in silicon, ion implantation and subsequent annealing are used to create emitters in wafers at a desired density. However, ion implantation introduces damage and additional defects into the silicon lattice, potentially impacting charge environments local to color centers. In this project, we focus on the creation of silicon T centers, which are point defects composed of two carbon atoms, and one hydrogen atom. We propose to use epitaxially grown...

Point defects in crystalline materials can introduce localized defects states with optical transitions, creating color centers. Color centers in silicon have recently shown their potential as telecom-band single photon emitters. Leveraging the mature semiconductor fabrication techniques, silicon color centers can be fabricated on a large scale and are compatible with integrated photonics. Among all the silicon color centers investigated so far, T centers provide a spin-photon interface suitable for quantum networking and communication applications. In this project, we demonstrate coherent...