CAN NUCLEAR-MAGNETIC-RESONANCE RESOLVE EPITAXIAL LAYERS

The recently demonstrated technique of time-sequenced optical nuclear magnetic resonance in GaAs has made possible the detection of spectra free of the line shape distortions that accompanied earlier steady-state methods with an improvement in sensitivity as well. This work examines the possibility of even higher spectral resolution by means of selective averaging with radio frequency-optical multiple-pulse techniques with the aim of isolating the site-specific changes in the spin Hamiltonian associated with excitation to localized states of the conduction band, as in quantum wells. Simulations are presented to evaluate the approach proposed. It is concluded that such experiments are capable of the sensitivity and resolution to resolve individual epitaxial layers in high-quality structures and would provide unprecedented detail on the electronic structure and its uniformity by way of the nuclear quadrupole and spin-averaged hyperfine interactions.