Theoretical model of dynamic spin polarization of nuclei coupled to paramagnetic point defects in diamond and silicon carbide

• Published in: Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2015-09, Vol.92 (11), p.115206, Article 115206
• Main Authors: Ivády, Viktor, Szász, Krisztián, Falk, Abram L., Klimov, Paul V., Christle, David J., Janzén, Erik, Abrikosov, Igor A., Awschalom, David D., Gali, Adam
• Format: Article
• Language: English
• ISSN: 1098-0121; 1550-235X; 1550-235X
• DOI: 10.1103/PhysRevB.92.115206

Dynamic nuclear spin polarization (DNP) mediated by paramagnetic point defects in semiconductors is a key resource for both initializing nuclear quantum memories and producing nuclear hyperpolarization. DNP is therefore an important process in the field of quantum-information processing, sensitivity-enhanced nuclear magnetic resonance, and nuclear-spin-based spintronics. DNP based on optical pumping of point defects has been demonstrated by using the electron spin of nitrogen-vacancy (NV) center in diamond, and more recently, by using divacancy and related defect spins in hexagonal silicon carbide (SiC). Here, we describe a general model for these optical DNP processes that allows the effects of many microscopic processes to be integrated. Applying this theory, we gain a deeper insight into dynamic nuclear spin polarization and the physics of diamond and SiC defects. Our results are in good agreement with experimental observations and provide a detailed and unified understanding. In particular, our findings show that the defect electron spin coherence times and excited state lifetimes are crucial factors in the entire DNP process.