Hybrid functional calculations of electronic structure and carrier densities in rare-earth monopnictides

TL;DR

This paper uses advanced hybrid functional DFT calculations to accurately determine the electronic structure and carrier densities of rare-earth monopnictides, improving agreement with experimental data over previous methods.

Contribution

The study applies HSE06 hybrid functional calculations to RE-V compounds, providing more accurate electronic and carrier density data compared to traditional DFT-GGA methods.

Findings

RE-V compounds are semimetals with specific electron and hole pockets.

HSE06 yields carrier densities consistent with experimental measurements.

DFT-GGA overestimates carrier densities.

Abstract

The structural parameters and electronic structure of rare-earth pnictides are calculated using density functional theory (DFT) with the Heyd, Scuseria, and Ernzerhof (HSE06) screened hybrid functional. We focus on RE-V compounds, with RE=La, Gd, Er, and Lu, and V=As, Sb, and Bi, and analyze the effects of spin-orbit coupling and treating the RE 4$f$ electrons as valence electrons in the projector augmented wave approach. The results of HSE06 calculations are compared with DFT within the generalized gradient approximation (DFT-GGA) and other previous calculations. We find that all these RE-V compounds are semimetals with electron pockets at the $X$ point and hole pockets at $\Gamma$. Whereas in DFT-GGA the carrier density is significantly overestimated, the computed carrier densities using HSE06 is in good agreement with the available experimental data.