Charge State Dynamics and Quantum Sensing with Defects in Diamond

In recent years, defect centers in wide band gap semiconductors such as diamond, have received significant attention. Defects offer great utility as single photon emitters, nanoscale sensors, and quantum memories and registers for quantum computation. Critical to the utility of these defects, is their charge state. In this dissertation, experiments surrounding the charge state dynamics and the carrier dynamics are performed and analyzed. Extensive studies of the ionization and recombination processes of defects in diamond, specifically, the Nitrogen Vacancy (NV) center, have been performed. Diffusion of ionized charge carriers has been imaged indirectly through the recapture of said carriers by optically active defects such as the NV center and the Silicon Vacancy (SiV) center. With proper understanding of the carrier dynamics, diamond stands to be a strong competitor in the field of spintronics for quantum information processing. Additionally, the understanding of these charge state dynamics is utilized in a novel proof of principle experiment, showing that the NV center defect’s charge state could serve as an ultra-dense 3D memory platform. The NV center has also been used as a nanoscale magnetometer. The high degree of spin polarization and the ease of manipulation of the NV allows us to transfer this polarization to other spins in the diamond and assists in the detection of spins outside of the diamond. Ensembles of Nitrogen Vacancy centers can be used to perform NMR spectroscopy of sample volumes not achievable through traditional methods. The operating mechanisms of the magnetic resonance aspects of the NV center will be discussed in depth. Work surrounding the control and polarization of the NV center’s host nitrogen spin will be covered. The topic of sensitivity and methods to improve that sensitivity will be covered as well