Novel magnetic-sensing modalities with nitrogen-vacancy centers in diamond

Abstract

Precision measurement of magnetic fields is critical to many applications in fundamental science and technology, geology, biology, medicine, security, and materials and space sciences. These applications require operation under a wide range of specifications regarding sensitivity, spatial resolution, bandwidth, scalability, pressure and temperature. Work within this thesis advances research into implementations of magnetic sensing using nitrogen-vacancy (NV) centers, defects in diamond that have become increasingly favored in the magnetometry community due to their small size, high spatial resolution, ability to operate over large temperature and pressure ranges, and wide bandwidth. Specifically, this dissertation presents novel techniques for magnetometry with NV centers---microwave (MW)-free magnetometry based on the ground-state level anticrossing and zero-field magnetometry realized with circularly polarized MWs---which extends the dynamic range of magnetic sensing and opens up new avenues of application. Additionally, the MW-free sensing protocol is further extended to a vector magnetometer that can simultaneously measure all Cartesian components of a magnetic field. All the investigated techniques are demonstrated with NV ensembles but these are potentially applicable to single-NV sensors as well. Finally, I outline a plan for improving these sensors to study micro- and nano- scale magnetic phenomena currently inaccessible using existing technology.