A high-resolution Compton scattering study of Cu : experiment and theory

Abstract We present [100], [110] and [111] Compton profiles of Cu at a high momentum resolution of 0.12 au, together with the corresponding highly accurate band theory computations. The theoretical and experimental results are compared and contrasted with focus on the shape and anisotropy of the profile. A reasonable overall picture of the ground state momentum density of Cu is adduced, and the deviations from the band theory predictions based on the local density approximation (LDA) are consistent with those found in recent high-resolution studies of Li and Be. This study provides further evidence that the high-resolution Compton techniques offers a unique window on electron correlation effects, and that a satisfactory description of the momentum density in solids requires a treatment of correlation effects beyond the LDA framework.