Entwicklung und Optimierung schneller mehrdimensionaler NMR-Experimente

Die vorliegende Arbeit umfasst die Entwicklung und Optimierung schneller mehrdimensionaler Experimente in der NMR-Spektroskopie für kleine Moleküle. Diese ermöglichen die Aufnahme heteronuklearer Korrelationsspektren in natürlicher Isotopenhäufigkeit in wenigen Sekunden. Zeitlich liegen sie damit im Bereich herkömmlicher Protonen-1D-Experimente, bei gleichzeitig erhöhter Signaltrennung durch die zusätzliche Aufspaltung der Resonanzen entlang der Frequenzachse des Heterokerns

Optically induced dynamic nuclear spin polarisation in diamond

The sensitivity of Magnetic Resonance Imaging (MRI) depends strongly on nuclear spin polarisation and, motivated by this observation, dynamical nuclear spin polarisation has recently been applied to enhance MRI protocols (Kurhanewicz, J., et al., Neoplasia 13, 81 (2011)). Nuclear spins associated with the 13 C carbon isotope (nuclear spin I = 1/2) in diamond possess uniquely long spin lattice relaxation times (Reynhardt, E.C. and G.L. High, Prog. in Nuc. Mag. Res. Sp. 38, 37 (2011)) If they are present in diamond nanocrystals, especially when strongly polarised, they form a promising contrast agent for MRI. Current schemes for achieving nuclear polarisation, however, require cryogenic temperatures. Here we demonstrate an efficient scheme that realises optically induced 13 C nuclear spin hyperpolarisation in diamond at room temperature and low ambient magnetic field. Optical pumping of a Nitrogen-Vacancy (NV) centre creates a continuously renewable electron spin polarisation which can be transferred to surrounding 13 C nuclear spins. Importantly for future applications we also realise polarisation protocols that are robust against an unknown misalignment between magnetic field and crystal axis.Comment: This is the revision submitted to NJ