Momentum density, Fermi surface and directional Compton profile in the Iron-based superconductor LaOFeAs

We have carried out first principles all-electron calculations of the (001) projected 2D electron momentum density (2D-EMD) and directional Compton profiles (CPs) along the [100], [001], and [110] directions in iron-based superconductor LaO$_{1-x}$F$_{x}$FeAs for various doping concentrations $x$ within the framework of the local density approximation (LDA). We have identified Fermi surface features both in the 2D-EMD and in the CPs. Bonding effects related to the character of wave functions near the Fermi level are revealed by the autocorrelation function B(r) defined as the Fourier transform of the momentum density. Work supported in part by the US Department of Energy.