Band structure of LaB6 by an algorithm for filtering reconstructed electron-positron momentum densities

TL;DR

This paper introduces a new filtering algorithm for three-dimensional electron-positron momentum densities, applied to LaB6, revealing detailed electronic structure features and the influence of electron-electron correlations.

Contribution

A novel filtering method for 3D reconstructed densities is developed and applied to LaB6, improving analysis of electronic structures from 2D ACAR spectra.

Findings

Good agreement between experimental and theoretical band structures

Detection of small electron pockets in the 15th band

Electron-electron correlations significantly affect momentum density

Abstract

A new method (NM) for filtering three-dimensional reconstructed densities is proposed. The algorithm is tested with simulated spectra and employed to study the electronic structure of the rare-earth compound LaB6. For this system, momentum densities are reconstructed from theoretical and experimental two-dimensional angular correlation of electron-positron annihilation radiation (2D ACAR) spectra. The experimental results are in good agreement with the band structure calculated with the full-potential linearized augmented-plane-wave (FLAPW) method within the local-density approximation (LDA), apart from the detection of small electron pockets in the 15th band. It is also shown that, unlike the electron-positron enhancement, the electron-electron correlations affect noticeably the momentum density.