Combining semi-local exchange with dynamical mean-field theory: electronic structure and optical response of rare-earth sesquioxides

Abstract

In rare-earth semiconductors, wide ligand $p$ and rare-earth 5$d$ bands coexist with localized, partially filled 4$f$ shells. A simultaneous description for both extended and localized states represents a significant challenge for first-principles theories. Here, we combine an {\it ab initio} dynamical mean-field theory approach to strong local correlations with a perturbative application of the semi-local modified Becke-Johnson exchange potential to correct the semiconducting gap. We apply this method to calculate the electronic structure and optical response of the light rare-earth sesquioxides RE${}_2$O${}_3$ (RE= La, Ce, Pr and Nd). Our calculations correctly capture a non-trivial evolution of the optical gap in RE${}_2$O${}_3$ due to a progressive lowering of the 4$f$ states along the series and their multiplet structure. 2$p$ $-$ 4$f$ hybridization is found to induce a substantial upward shift for the occupied 4$f$ states occurring within the $p-d$ gap, thus reducing the magnitude of the optical gap. We show that a characteristic plateau observed in the optical conductivity in the Pr and Nd sequioxides right above their absorption edge is a fingerprint of 4$f$ states located within the $p-d$ gap.

arXiv comment9 pages, 4 figures

References in corpus (23)

• Electronic Structure Calculations with Dynamical Mean-Field Theory: A Spectral Density Functional Approach
• Continuous-time Monte Carlo methods for quantum impurity models
• A continuous-time solver for quantum impurity models
• First-principles Calculations of the Electronic Structure and Spectra of Strongly Correlated Systems: Dynamical Mean-field Theory
• TRIQS: A Toolbox for Research on Interacting Quantum Systems
• First principles approach to the electronic structure of strongly correlated systems: combining GW and DMFT
• TRIQS/CTHYB: A Continuous-Time Quantum Monte Carlo Hybridization Expansion Solver for Quantum Impurity Problems
• The nature of the electronic band gap in lanthanide oxides
• TRIQS/DFTTools: A TRIQS application for ab initio calculations of correlated materials
• First principles study of rare-earth oxides
• The f-electron challenge: localized and itinerant states in lanthanide oxides united by GW@LDA+U
• Self-consistency over the charge-density in dynamical mean-field theory: a linear muffin-tin implementation and some physical implications
• Questaal: a package of electronic structure methods based on the linear muffin-tin orbital technique
• Importance of electronic correlations for structural and magnetic properties of the iron pnictide superconductor LaFeAsO
• Standard model of the rare-earths, analyzed from the Hubbard I approximation
• Maximum entropy formalism for the analytic continuation of matrix-valued Green's functions
• A Self-consistent DFT+DMFT scheme in the Projector Augmented Wave : Applications to Cerium, Ce2O3 and Pu2O3 with the Hubbard I solver and comparison to DFT+U
• Charge self-consistency in density functional theory + dynamical mean field theory: k-space reoccupation and orbital order
• Multiplets Matter: The Electronic Structure of Rare-Earth Semiconductors and Semimetals
• Self-consistent GW method: O(N) algorithm for polarizability and self energy
• Physical properties of the trigonal binary compound Nd${}_2$O${}_3$
• Combining the Hybrid Functional Method with Dynamical Mean-Field Theory
• Correlated electronic structure and optical response of rare-earth-based semiconductors

Cited by in corpus (3)

• Electronic structure of rare-earth mononitrides: quasiatomic excitations and semiconducting bands
• Multipolar interactions and magnetic excitation gap in d${}^3$ spin-orbit Mott insulators
• Relation between crystal structure and optical properties in the correlated blue pigment YIn${}_{1-x}$Mn${}_x$O${}_3$