Spins in diamond and silicon carbide for quantum networks

Abstract

Electron-spin qubits associated to solid-state defects can exhibit exceptional optical and spin coherence. Additionally, magnetic interactions with surrounding spins presents a resource for multi-qubit registers. Combined, this makes such solid-state defect systems promising for quantum network applications. In this thesis, we first realize a toolbox to control electron-nuclear spin qubits surrounding an NV-center in diamond and investigate such spins as potential qubits by generating an entangled state shared amongst two spins. Secondly, we improve the robustness of a nuclear-spin memory qubit while emulating remote entanglement generation protocols. Ancillary (spectator) qubits subject to noise correlated to the memory qubit are measured and subsequent feedforward allows to mitigate this noise in real-time. Thirdly, we investigate spectral diffusion dynamics in commercially available silicon carbide and demonstrate (near-)Fourier linewidth limited optical transitions within a broad inhomogeneously broadened spectrum. Finally, an outlook on electron spin clusters and photonic integration of electron spins is presented.