Optimization of electron-nuclear polarization transfer

Optimal-control-based numerical algorithms make it possible to explore the physical limits of dynamic nuclear polarization. Examples of time-optimal and relaxation-optimized electron-nuclear polarization transfer experiments are presented for simple model systems consisting of an isolated electron-nuclear spin pair in the absence and presence of relaxation. The optimized pulse sequences are compared with conventional transfer schemes, such as electron-nuclear cross polarization and selective population inversion.