| Nitrogen-Vacancy (NV) center was a point defect in diamond with stable fluores-cence and long electron spin coherence time. It was widely used in quantum computa-tion, nanoscale magnetometry, nanophotonics, and biological labelling. In almost all the experiment, optical methode was used to polarize and detect the NV center electron spin state. However, experimental study showed that photochromic was observed with NV center. The NV center fluorescence intensity and wavelength was changed by different laser. In the lower temperature resonant exciation experiment, the photochromism of NV center induced the Zero Phonon Line diffussion.Photochromism was simply defined as a reversible change between two forms of a chemical species under photon excitation. Not only the absorption and fluorescence spectrum of the materials were changed, but also other properties, as the refractive and conductivity. Obviously the photochromism will affect the application of NV center, studies showed that the photochromism of NV center might be induced by the charge state conversion. But the exact optical transition process was not very clear, and the population of NV-charge state was always lower than75%. It needs more experi-mental works to study the mechanism of photochromism of NV. In order to improve the performance of NV center in quantum computing and metrology, we also need to know the influence of photochromism to NV center spin state, find out whether the photochromism would depolarize the spin state. Subsequently, we expected the pho-tochromism can expand the application of NV center.Therefore, we have done a series of experiments to study the mechanism and ma-nipulation of NV center photochromism:1. The NV center was produced by ion implantation, and the properties of sin-gle NV center was measured. Using the home-built optical and microwave setup, we demonstrated the possibility of NV center temperature sensor by the study of the tem-perature dependence of NV center energy level. And we have used a single NV center to detect the magentic field vector.2. We used charge state non-destructive measurment to study the photochromism with different laser. It demonstrated the photochromism was induced by charge state conversion. With the manipulation of spin state, we increased the population of NV-up to80%.3. The impact of photochromism was examined by measuring the spin rabi os-cillation and second order correlation function. The results showed that the affect of photochromism was differeny with different lasers.4. We realized the microscopy with resolution below50nm by manipulation the NV center photochromism with different laser, and measured the electron spin resonance signal with high resolution. It could be used for nanoscale sensor and labeling with NV center.This thesis was organized as follows, In the first chapter, we will introduce the defination and study of photochromism. In the second chapter, we will introduce the optical and spin properties of NV center, as well as the method to detect single NV center. The third chapter presented our works on the NV center sensor. In the fourth chapter, we will discuss the mechanism and measurement of NV center photochromism. The fifth chapter experimentally studied the affect of photochromism to spin and optical properties of NV center. In the sixth chapter, we developed a method to control the charge state of NV center with high spatial resolution, and used it to detect the electron spin resonance signals with resolution belowe diffraction limit. The seventh chapter summarized our works.Recently, peoples paid more and more attention to the charge state conversion of NV center. Our works could help to control the NV center charge state, and improve the fidelity of quantum conputation and metrology. But the microscopic explanation of NV center equilibrium charge state needs more experimental and theoretical studies. In the following works, we will further improve the spatial resolution of charge state control, and use this method to study the dynamics of coupled NV center dimer; also, we will continue to optimize the method for NV center charge state manipulation to improve the population of NV-... |
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