UC San Diego

The nitrogen-vacancy center has been an active subject of investigation for decades. Recently however, the pace of this research has accelerated dramatically to take advantage of the superlative qualities possessed by these optically active defects in diamond, including their extended quantum coherence, single-spin addressability, and their ability to probe magnetic fields non-invasively and with ultra-high sensitivity in a broad temperature range. The peculiar qualities of NV centers, including their diverse and extraordinary modes of measurement, are explored in this dissertation. From basic diamond nanostructures, to the cutting-edge scanning modes of research, the development and implementation of various techniques in NV magnetometry are hereafter traced. Along the way, these methods are applied to VO2 (a Mott insulator), FTS (a 2D superconductor possessing a ferromagnetic moment), the MnBi2Te4 (Bi2Te3)n class of materials possessing non-trivial quantum transport properties, and to the study of domain walls in [Co-Ni] multilayer heterostructures. These studies were conducted using a combination of home-built confocal and widefield microscope setups, and commercially acquired scanning measurement systems. In this, I hope to document a journey of understanding and utilization of the NV center defect, starting from basic applications through to the current state-of-the-art. The NV center is likely the most studied optically active intrinsic spin qubit to date, but these methods may be expanded and applied to a whole class of optical defects in diamond, silicon carbide, and now 2-dimensional van der Waals heterostructure systems. The countless opportunities these studies present in the field of quantum computation and quantum sensing are just beginning to emerge.