Optical Larmor Beat Detection of High-Resolution Nuclear Magnetic Resonance in a Semiconductor Heterostructure

Abstract

A new method of optical nuclear magnetic resonance, Larmor beat detection, is described and demonstrated on a III-V semiconductor heterostructure. 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 field, while NMR transients of a second isotope are observed optically in real time. Order-of-magnitude improvement in resolution and sensitivity over previous techniques is obtained, revealing weak electric field gradients in single epitaxial structures.