New approaches to ultrasensitive magnetic resonance

Spectroscopic methods tend to exhibit an inverse correlation between sensitivity and the ability to discriminate between similar structures. Were they obtainable with adequate sensitivity, magnetic resonance spectra could resolve structural controversies involving the nature of clusters, ions, semiconductor defects and catalytic intermediates. This paper describes several novel approaches to magnetic resonance, which have in common that the spins are coupled to other degrees of freedom in order to obtain nonequilibrium polarization and/or greater detection sensitivity. The methods under development include single-ion electron spin resonance detected by ion trapping frequencies, catalyst NMR detected by the branching ratio to different spin symmetry species and semiconductor nuclear magnetic resonance detected via the circular polarization of luminescence