Multiple quantum inversion in scalar coupled systems with amplitude modulated temporally overlapped pulses.

In this paper we propose the extension of stimulated Raman adiabatic passage, a popular technique in optics for population inversion in three-level systems, to the NMR regime. The technique employs two amplitude modulated pulses-the first connecting the final and intermediate states followed by a second partially overlapped in time with it and connecting the ground and intermediate states. We present computer simulations demonstrating the applicability of the technique in NMR although we are no longer dealing with "pure" states, unlike in optics. Double quantum population inversion in two- and three-spin scalar coupled systems provides experimental support to our proposal.