The silicon T centre hyperfine tensor and a proposal for coherence protection

Synopsis

The T centre is an emerging defect in silicon that can be used as a spin-photon interface for constructing quantum networks. It contains hyperfine-coupled nuclear and electron spins that are well suited for brokered entanglement generation. Their shared hyperfine interaction enables local two-qubit gates. The hydrogen nuclear spin can be used as a client for storing entanglement during optical entanglement attempts between remote broker electron qubits. In this thesis, I determine the anisotropic hyperfine tensor (within two possible principal cases) by fitting optically detected magnetic resonance spectra of the T centre’s ground state in purified 28Si. The hyperfine interaction can decohere the nuclear qubit during entanglement attempts as it interacts with the broker system. I propose applying magnetic fields along a manifold where an effective hyperfine constant vanishes in order to protect nuclear coherence.