NUCLEAR-SPIN DIFFUSION VIA SPIN-EXCITONS IN THE QUANTUM HALL-EFFECT REGIME

Nuclear-spin diffusion, via exchange of spin-excitons, in two-dimensio nal electron systems under strong magnetic field is considered. It is shown that the nuclear spin polarization can be transported on distanc e d, large compared to the magnetic length. l(B). This leads to new po ssibilities of studying electron interactions in sufficiently dean het erojunctions, where impurity scattering and long-range potential fluct uations are too weak to generate significant relaxation rate for the n uclear spins.