OPTICAL LARMOR BEAT DETECTION OF HIGH-RESOLUTION NUCLEAR-MAGNETIC-RESONANCE IN A SEMICONDUCTOR HETEROSTRUCTURE

A new method of optical nuclear magnetic resonance, Larmor beat detect ion, is described and demonstrated on a III-V semiconductor heterostru cture. Modulation of the circular polarization of luminescence at the difference between two nuclear spin precession frequencies is induced by rf pulses. One isotope provides a spin-locked reference held, while NMR transients of a second isotope are observed optically in real tim e. Order-of-magnitude improvement in resolution and sensitivity over p revious techniques is obtained, revealing weak electric held gradients in single epitaxial structures.