UBC Theses and Dissertations
The direct detection of double quantum coherence Legros, Mark Anthony
When a spin-1 nucleus is placed in a large magnetic field and an electric field gradient, the energy level diagram for the states describing it's orientation consist of three unequally spaced levels. If the hamiltonian (which is the sum of a Zeeman term and a quadrupolar term) is truncated to include only terms which commute with the Zeeman term, magnetic dipole transitions between levels with m=1 have finite transition probabilities. When the nonsecular terms, those which do not commute with lz, are taken into account another magnetic dipole transition can occur; a transition in which m=2. The theory and experimental techniques associated with the observation of m=2 transitions is presented. The intention is to provide insights and examples of when the spectroscopy of such transitions is a valuable procedure. The results show that the spectroscopy of this forbidden transition is practical for spin-1 nuclei in systems with large (>500Khz) quadrupole splittings, and long spin-spin relaxation times. The information available by doing the m=2 experiments is obtainable from other resonance techniques and the major feature which prevents the experiments from being relegated to the catagory of a "Scientific curiosity" is their simplicity.
Item Citations and Data