Magnetometry with Ensembles of Nitrogen Vacancy Centers in Bulk Diamond

This thesis summarizes experiments conducted to develop a high sensitivity vector magnetometer using nitrogen vacancy (NV) centers in a bulk diamond sample. This project began by analyzing the sensitivity of a single NV orientation using a continuous wave electron spin resonance approach. A protocol for determining the diamond's orientation was developed to map vector magnetic field readings in the diamond reference frame to the lab frame. Preliminary vector field measurements and differential vector measurements were performed. Although these showed promising results, significant instrument and ambient magnetic noise limited the achievable sensitivity. A new frequency locking measurement technique was developed to allow for simultaneous measurements between two separate sensors for future differential experiments. This technique provides a host of other benefits including much improved dynamic range and steady-state immunity to fluctuations in linewidth and contrast. Thesis Supervisor: Dirk Englund Title: Assistant Professor Thesis Supervisor: Danielle Braje Title: Research Scientist