PhD Thesis Defense: Christopher Paul Anderson

3:00 pm

This thesis investigates the development of quantum technologies with spins in silicon carbide (SiC). In particular, SiC can host optically active defect spins which are key to developing solid-state quantum sensors, communications networks, and distributed quantum computation over long distances. The neutral divacancy (VV0) is such a spin defect, which displays long coherence times and possesses a spin-photon interface for long-distance entanglement. Throughout this thesis, we leverage the distinct advantages that SiC has as a host material for quantum bits. Broadly, we describe how quantum states can be controlled, tuned, and enhanced through their integration into SiC mechanical, photonic and electrical devices. 

Specifically, this thesis focuses on understanding and controlling the electrical environment of single qubits. Electrical and optical control of the charge state of defects is achieved in ensembles and is extended to single VV0  that are isolated and manipulated in wafer scale, commercial semiconductor p-i-n diodes. We find that through this integration an ideal, widely tunable, and spectrally narrow spin-photon entanglement interface is created. This pathway for eliminating spectral diffusion in doped semiconductor devices unlocks the possibility of efficient long distance quantum entanglement in the solid-state. This thesis further develops VV0 for quantum technologies by extending the coherence times of this system and by demonstrating control and entanglement between electron and nuclear spins in SiC. Combining the mature semiconductor industry for SiC semiconductor devices with coherent single spins with high-fidelity spin-photon interfaces provides an exciting avenue for scalable quantum technologies in the solid-state.

Committee Members:

David Awschalom (Chair)

David Schuster

Shinsei Ryu

John Carlstrom

Event Type

Thesis Defense

May 1