Optically detected nuclear magnetic resonance of nuclei within a quantum well

Observations are reported of nuclear magnetic resonance (NMR) for nuclei in single GaAs/AlGaAs quantum wells, using an optical pumping and detection scheme. The technique gives signals only from nuclei in contact with the quantum-confined electron wavefunction and therefore discriminates against substrate and barrier nuclei. Some general factors which affect the strength of signals are discussed and preliminary results are presented which show the potential of NMR for measuring strain in pseudomorphic systems and for detecting and identifying impurities.