Quantum NV magnetometry towards single nuclear spin limit

Abstract

In this thesis, I have developed a NV magnetometer and demonstrated nanoscale NMR with single nuclear spin sensitivity. Firstly, I introduce the basic physics and essential properties of NV center in diamond and NV magnetometry. And its applications in material, biology and physics is introduced. Secondly, the multi-pass protocols is investigated to enhance sensitivity and it is demonstrated that the high-order dynamical decoupling pulse sequence can be implemented in magnetometry. Thirdly, a series of periodical dynamical decoupling pulse sequences in single and double transition are compared. Then the anomalous decoherence effect of 12C nuclear spin ensemble is found useful in controlling of weakly coupled nuclear spin ensemble. Fourthly, we study NMR spectroscopy in the strong coupling regime. Nuclear magnetic resonance spectroscopy of four 29Si nuclear spins is performed. We exploit the field gradient created by the diamond atomic sensor, in concert with compressed sensing, to realize imaging protocols, enabling individual nuclei to be located with angstrom precision. The achieved signal-to-noise ratio under ambient conditions allows single nuclear spin sensitivity to be achieved within seconds. Besides, I try to improve the spectral line-width using correlation spectroscopy. Finally, we sense and characterize the interactions between a single 13C-13C nuclear spin dimer located about 1nm from the NV center. From the measured interaction we derive the spatial configuration of the dimer with atomic-scale resolution. These results indicate that, in combination with advanced material-surface engineering, central spin decoherence under dynamical decoupling control may be a useful probe for nano-scale nuclear magnetic resonance single-molecule structure analysis.