Nuclear magnetic resonance molecular photography

摘要

A procedure is described for storing a two-dimensional (2D) pattern consisting of 32 X 32 = 1024 bits in a spin state of a molecular system and then retrieving the stored information as a stack of nuclear magnetic resonance spectra. The system used is a nematic liquid crystal, the protons of which act as spin clusters with strong intramolecular interactions. The technique used is a programmable multifrequency irradiation with low amplitude. When it is applied to the liquid crystal, a large number of coherent long-lived ~1H response signals can be excited, resulting in a spectrum showing many sharp peaks with controllable frequencies and amplitudes. The spectral resolution is enhanced by using a second weak pulse with a 90 deg phase shift, so that the 1024 bits of information can be retrieved as a set of well-resolved pseudo-2D spectra reproducing the input pattern.