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arXiv · 2101.01463

Correlated electronic structure and optical response of rare-earth-based semiconductors

Anna Galler·James Boust·Alain Demourgues·Silke Biermann·Leonid V. Pourovskii
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Abstract

Simultaneous occurrence of the Mott and band gap in correlated semiconductors results in a complex optical response with the nature of the absorption edge difficult to resolve both experimentally and theoretically. Here, we combine a dynamical mean-field theory approach to localized 4f shells with an improved description of band gaps by a semi-local exchange-correlation potential to calculate the optical properties of the light rare-earth fluorosulfides LnSF (Ln=Pr, Nd, Sm, Gd) from first principles. In agreement with experiment, we find the absorption edge in SmSF to stem from S-3p to Sm-4f transitions, while the Gd compound behaves as an ordinary p-d gap semiconductor. In the unexplored PrSF and NdSF systems we predict a rather unique occurrence of strongly hybridized 4f-5d states at the bottom of the conduction band. The nature of the absorption edge underlies a peculiar anisotropy of the optical conductivity in each system.

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Anna Galler, James Boust, Alain Demourgues, Silke Biermann, Leonid V. Pourovskii. 2021-01-05. Correlated electronic structure and optical response of rare-earth-based semiconductors. https://doi.org/10.1103/physrevb.103.l241105

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