  We report a method for nanometer-scale pulsed nuclear magnetic resonance
imaging and spectroscopy. Periodic radiofrequency pulses are used to create
temporal correlations in the statistical polarization of a solid organic
sample. The spin density is spatially encoded by applying a series of intense
magnetic field gradient pulses generated by focusing electric current through a
nanometer-scale metal constriction. We demonstrate this technique using a
silicon nanowire mechanical oscillator as a magnetic resonance sensor to image
1H spins in a polystyrene sample. We obtain a two-dimensional projection of the
sample proton density with approximately 10-nm resolution.
