  The effect of dipolar and exchange interactions within pairs of paramagnetic
electronic states on Pauli-blockade-controlled spin-dependent transport and
recombination rates during magnetic resonant spin excitation is studied
numerically using the superoperator Liouville-space formalism. The simulations
reveal that spin-Rabi nutation induced by magnetic resonance can control
transition rates which can be observed experimentally by pulsed electrically
(pEDMR) and pulsed optically (pODMR) detected magnetic resonance
spectroscopies. When the dipolar coupling exceeds the difference of the pair
partners' Zeeman energies, several nutation frequency components can be
observed, the most pronounced at sqrt{2} gamma B_1 (gamma is the gyromagnetic
ratio, B_1 is the excitation field). Exchange coupling does not significantly
affect this nutation component; however, it does strongly influence a
low-frequency component < gamma B_1. Thus, pEDMR/pODMR allow the simultaneous
identification of exchange and dipolar interaction strengths.
