Enhancement of nuclear spin coherence times by driving dynamic nuclear polarization at defect centers in solids

• Published in: arXiv.org
• Main Authors: Sharma, Gargee, Gaebel, Torsten, Rej, Ewa, Reilly, David J, Economou, Sophia E, Barnes, Edwin
• Format: Paper Journal Article
• Language: English
• Published: Ithaca Cornell University Library, arXiv.org 08.05.2019
• Subjects: Coherence; Defects; Diamonds; Nanostructure; Nuclear spin; Physics - Mesoscale and Nanoscale Physics; Polarization; Spin dynamics
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1810.06542

The hyperpolarization of nuclear spins can enable powerful imaging and sensing techniques provided the hyperpolarization is sufficiently long-lived. Recent experiments on nanodiamond \(^{13}\)C nuclear spins demonstrate that relaxation times can be extended by three orders of magnitude by building up dynamic nuclear polarization (DNP) through the driving of electron-nuclear flip-flop processes at defect centers. This finding raises the question of whether the nuclear spin coherence times are also impacted by this hyperpolarization process. Here, we theoretically examine the effect of DNP on the nuclear spin coherence times as a function of the hyperpolarization drive time. We do this by developing a microscopic theory of DNP in a nuclear spin ensemble coupled to microwave-driven defect centers in solids and subject to spin diffusion mediated by internuclear dipolar interactions. We find that, similarly to relaxation times, the nuclear spin coherence times can be increased substantially by a few orders of magnitude depending on the driving time. Our theoretical model and results will be useful for current and future experiments on enhancing nuclear spin coherence times via DNP.