My doctoral thesis was a study of â€śMagnetic Field Effects in Chemical Systemsâ€?, which was supervised by Prof Peter Hore and Dr Christiane Timmel. I was a member of St John’s College and the Physical and Theoretical Chemistry Lab.
In the last decade, the Hore and Timmel groups have developed a range of experiments using both static and radio frequency fields under time-resolved and steady-state conditions. Systems have been studied in homogeneous and micellar solutions and field effects have been optimized with respect to temperature, viscosity, solvent dielectric constant and micellar size. A consistent body of theory has been developed, using quantum mechanics in the (spin) density matrix formalism. Where prudent, we have borrowed a number of ideas from the magnetic resonance literature, adapting them to the unique conditions at very low magnetic fields.
During my doctoral studies, I developed the theoretical interpretation of these results by introducing several novel theoretical methods. For example, I adapted an algorithm called Îł-COMPUTE from use in the field of solid state NMR to simulate experiments involving radio frequency magnetic fields. I also developed an efficient method for calculating the response to time-independent magnetic fields in systems containing a physically realistic number of magnetic nuclei (e.g. 1H or 15N). I also performed Monte Carlo calculations comparing a semi-classical approximation with exact quantum mechanical calculations for many different species in order to develop a set of empirical rules for the interpretation of magnetic field effect data. Each body of new theory has been developed in tandem with experiments performed in the Timmel group. In this manner, we ensure that the theory is firmly grounded in experiment and vice-versa.