In this Letter the possibility of selective excitation in coupled multispin systems is studied theoretically. A general method of transforming any selective pulse developed for uncoupled systems into a form that is selective in coupled systems is presented. This is accomplished by adding a small perturbation to a decoupling radiofrequency (RF) field. When viewed in an interaction frame given by the decoupling RF field, this method generates, in an averaged sense, a propagator similar to the propagator of uncoupled spins under a shaped RF pulse. Preliminary experimental results are presented for the case of selective excitation in proton nuclear magnetic resonance in liquid crystals.
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This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences Division, U.S. Department of Energy under Contract No. DE-AC03-76SF00098.