Abstract
A two-photon annihilation study of the Fermi surface in high-purity copper single crystals has been carried out using angular correlation of annihilation radiation (ACAR). The measured momentum density distributions are compared with band-structure calculations to elucidate the details of the Fermi surface topology.
Key Results
The ACAR profiles reveal clear signatures of the electron-positron momentum correlation. The Fermi surface features are consistent with local-density approximation calculations, with deviations attributed to electron-positron correlation effects.
$$ J(\mathbf{p}\perp) = \int n(\mathbf{p}\perp, p_z) , dp_z $$