Control of spin currents with double spin resonance

This paper develops a theoretical picture for coherently controlling spin currents with two resonant transitions which bridge the Zeeman gap of a two-dimensional electron system. One spin flip transition is propelled by r.f. electron oscillations in a sloping magnetic field. The second transition is induced by microwaves. When both transitions are simultaneously resonant, spin flips are inhibited by a formation of a dark state. We calculate the probability of this dark state as the system crosses resonance and show that it fits the ESR peak in the resistance of a magnetic superlattice.