Alp Sipahigil (Advisor)

Transduction of signals between electrical, mechanical, and optical domains is central to modern computing, sensing, and communication systems. Emerging quantum computing, sensing, and communication technologies also require the development of transducers capable of converting quantum-level signals such as single photons and phonons with high efficiency and low loss. Traditional piezoelectric materials such as aluminum nitride and lithium niobate are widely used in classical piezoelectric and electro-optic transducers. However, for quantum applications, these thin films have large defect...

Achieving high-performance quantum computing with superconducting qubits requires a good understanding of the various loss mechanisms that can degrade qubit performance. One such potential loss mechanism is undesired electromechanical coupling mediated by piezoelectric effects. It can occur even in centrosymmetric materials due to interface symmetry breaking. In our recent cryogenic microwave transmission measurements, we observed such interface piezoelectricity at the aluminum-silicon heterostructure, a widely used material combination in superconducting qubit fabrication. This phenomenon...

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...