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Combining semilocal exchange with dynamical mean-field theory : Electronic structure and optical response of rare-earth sesquioxides

Boust, James ; Galler, Anna ; Biermann, Silke LU and Pourovskii, Leonid V. (2022) In Physical Review B 105(8).
Abstract

In rare-earth semiconductors, wide ligand p and rare-earth 5d bands coexist with localized, partially filled 4f shells. A simultaneous description for both extended and localized states represents a significant challenge for first-principles theories. Here, we combine an ab initio dynamical mean-field theory approach to strong local correlations with a perturbative application of the semilocal 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 R2O3 (R=La,Ce,Pr,andNd). Our calculations correctly capture a nontrivial evolution of the optical gap in R2O3 due to a progressive lowering of the 4f... (More)

In rare-earth semiconductors, wide ligand p and rare-earth 5d bands coexist with localized, partially filled 4f shells. A simultaneous description for both extended and localized states represents a significant challenge for first-principles theories. Here, we combine an ab initio dynamical mean-field theory approach to strong local correlations with a perturbative application of the semilocal 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 R2O3 (R=La,Ce,Pr,andNd). Our calculations correctly capture a nontrivial evolution of the optical gap in R2O3 due to a progressive lowering of the 4f states along the series and their multiplet structure. 2p-4f hybridization is found to induce a substantial upward shift for the occupied 4f 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 sesquioxides right above their absorption edge is a fingerprint of 4f states located within the p-d gap.

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author
; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Physical Review B
volume
105
issue
8
article number
085133
publisher
American Physical Society
external identifiers
  • scopus:85126064139
ISSN
2469-9950
DOI
10.1103/PhysRevB.105.085133
language
English
LU publication?
yes
id
05d90f49-d0bc-4556-ba94-cd92be39c881
date added to LUP
2022-06-15 13:21:24
date last changed
2025-04-04 15:19:57
@article{05d90f49-d0bc-4556-ba94-cd92be39c881,
  abstract     = {{<p>In rare-earth semiconductors, wide ligand p and rare-earth 5d bands coexist with localized, partially filled 4f shells. A simultaneous description for both extended and localized states represents a significant challenge for first-principles theories. Here, we combine an ab initio dynamical mean-field theory approach to strong local correlations with a perturbative application of the semilocal 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 R2O3 (R=La,Ce,Pr,andNd). Our calculations correctly capture a nontrivial evolution of the optical gap in R2O3 due to a progressive lowering of the 4f states along the series and their multiplet structure. 2p-4f hybridization is found to induce a substantial upward shift for the occupied 4f 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 sesquioxides right above their absorption edge is a fingerprint of 4f states located within the p-d gap.</p>}},
  author       = {{Boust, James and Galler, Anna and Biermann, Silke and Pourovskii, Leonid V.}},
  issn         = {{2469-9950}},
  language     = {{eng}},
  month        = {{02}},
  number       = {{8}},
  publisher    = {{American Physical Society}},
  series       = {{Physical Review B}},
  title        = {{Combining semilocal exchange with dynamical mean-field theory : Electronic structure and optical response of rare-earth sesquioxides}},
  url          = {{http://dx.doi.org/10.1103/PhysRevB.105.085133}},
  doi          = {{10.1103/PhysRevB.105.085133}},
  volume       = {{105}},
  year         = {{2022}},
}