High - precision electron - spin sensing with ensembles of nitrogen - vacancy centers in diamond

This thesis describes physical background and an experimental realization of a bulk diamond magnetic field and temperature sensor. The sensing is done using continuous-wave electronspin resonance spectra of nitrogen-vacancy centers in diamond. Experiments were performed using a light-trapping diamond waveguide sample, with which we estimate to address 10" nitrogen-vacancy centers simultaneously. We derive energy level structure of a nitrogenvacancy center and recover resonant frequencies of the ESR spectrum. Using the Lindblad master equation, we model ESR lineshape and for the first time consider the influence of infrared driving on the ESR contrast. Both continuous-wave and pulsed sensing protocols are described, and a novel reference-free temperature sensing scheme is proposed. In addition to building a laboratory setup for sensing, we discuss how to miniaturize the setup components and make an on-chip diamond sensor. In particular, we optimize the on-chip fluorescence collection apparatus. Finally, using the built laboratory setup, we demonstrate magnetic field sensitivity floor on the order of 1 nT/Hz1 / 2 and temperature sensitivity floor of 0.3 mK/Hz'/ 2 Thesis Supervisor: Dirk R. Englund Title: Assistant Professor of Electrical Engineering and Computer Science Thesis Supervisor: Vladan Vuletid Title: Professor of Physics