Topic: "Hyperfine Structure Interactions of the Energy Levels of Nitrogen–Vacancy Centers in Diamonds with Laser and Microwave Radiation in Magnetic Fields".
Scientific supervisor: Dr. habil. phys. Mārcis Auziņš.
Abstract:
Nitrogen-vacancy (NV) centers in diamond have become an interesting object of research over the past few decades. At the moment, research in the field of NV physics is transitioning from academic research to applied research and in some cases development of quantum sensor prototypes for specific applications. This work describes academic research on NV physics that is now applied for specific use case scenarios for precise detection and measurement of magnetic fields. The research described in this work includes NV fluorescence property studies at various know magnetic field values and how fluorescence measurements in combination with a known magnetic field source can be used for determination of unknown magnetic fields. Building on the fluorescence studies, the hyperfine energy level structure of the NV center for various magnetic field values is discussed in detail, specifically focusing at a region in the magnetic field where some of the energy levels undergo crossings and anti-crossings (energy level mixing). With this knowledge of the hyperfine structure of NV centers in diamond the properties of the nuclear spin of the nitrogen (14N) that is part of the NV center is studied in a broad range of magnetic field values (0 - 110 mT). For specific applications this can be used to increase the magnetic field sensitivity of a single axis magnetic field measurement due to the fact that most of the population is transferred to one hyperfine level (|mS = 0, mI = +1i).
Interaction between NV centers and other defects in a diamond lattice is also studied to gain insight on how these additional defects affect the NV center properties that in turn are important for certain applications, such as magnetic field measurements. The method used for studying the NV centers in this work is optically detected magnetic resonance (ODMR) which is a relatively simple and robust method making it very suitable for the development of compact, energy efficient application solutions.
Reviewers:
1) Dr. phys. Jana Andžāne, University of Latvia;
2) Dr. phys. Andrey Jarmola, University of California, Berkeley, USA;
3) Dr. Gergo Thiering, HUN-REN Wigner Research Centre for Physics, Hungary.
The doctoral thesis is available at the LU Library, Raiņa bulvāris 19.
Participation in the online session is by prior application, writing to sintija.silina@lu.lv by 10th of June.