---
_id: '44088'
abstract:
- lang: eng
  text: 'Hole polarons and defect-bound exciton polarons in lithium niobate are investigated
    by means of density-functional theory, where the localization of the holes is
    achieved by applying the +U approach to the oxygen 2p orbitals. We find three
    principal configurations of hole polarons: (i) self-trapped holes localized at
    displaced regular oxygen atoms and (ii) two other configurations bound to a lithium
    vacancy either at a threefold coordinated oxygen atom above or at a two-fold coordinated
    oxygen atom below the defect. The latter is the most stable and is in excellent
    quantitative agreement with measured g factors from electron paramagnetic resonance.
    Due to the absence of mid-gap states, none of these hole polarons can explain
    the broad optical absorption centered between 2.5 and 2.8 eV that is observed
    in transient absorption spectroscopy, but such states appear if a free electron
    polaron is trapped at the same lithium vacancy as the bound hole polaron, resulting
    in an exciton polaron. The dielectric function calculated by solving the Bethe–Salpeter
    equation indeed yields an optical peak at 2.6 eV in agreement with the two-photon
    experiments. The coexistence of hole and exciton polarons, which are simultaneously
    created in optical excitations, thus satisfactorily explains the reported experimental
    data.'
article_number: '1586'
article_type: original
author:
- first_name: Falko
  full_name: Schmidt, Falko
  id: '35251'
  last_name: Schmidt
  orcid: 0000-0002-5071-5528
- first_name: Agnieszka L.
  full_name: Kozub, Agnieszka L.
  id: '77566'
  last_name: Kozub
  orcid: 0000-0001-6584-0201
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
- first_name: Arno
  full_name: Schindlmayr, Arno
  id: '458'
  last_name: Schindlmayr
  orcid: 0000-0002-4855-071X
citation:
  ama: Schmidt F, Kozub AL, Gerstmann U, Schmidt WG, Schindlmayr A. A density-functional
    theory study of hole and defect-bound exciton polarons in lithium niobate. <i>Crystals</i>.
    2022;12(11). doi:<a href="https://doi.org/10.3390/cryst12111586">10.3390/cryst12111586</a>
  apa: Schmidt, F., Kozub, A. L., Gerstmann, U., Schmidt, W. G., &#38; Schindlmayr,
    A. (2022). A density-functional theory study of hole and defect-bound exciton
    polarons in lithium niobate. <i>Crystals</i>, <i>12</i>(11), Article 1586. <a
    href="https://doi.org/10.3390/cryst12111586">https://doi.org/10.3390/cryst12111586</a>
  bibtex: '@article{Schmidt_Kozub_Gerstmann_Schmidt_Schindlmayr_2022, title={A density-functional
    theory study of hole and defect-bound exciton polarons in lithium niobate}, volume={12},
    DOI={<a href="https://doi.org/10.3390/cryst12111586">10.3390/cryst12111586</a>},
    number={111586}, journal={Crystals}, publisher={MDPI AG}, author={Schmidt, Falko
    and Kozub, Agnieszka L. and Gerstmann, Uwe and Schmidt, Wolf Gero and Schindlmayr,
    Arno}, year={2022} }'
  chicago: Schmidt, Falko, Agnieszka L. Kozub, Uwe Gerstmann, Wolf Gero Schmidt, and
    Arno Schindlmayr. “A Density-Functional Theory Study of Hole and Defect-Bound
    Exciton Polarons in Lithium Niobate.” <i>Crystals</i> 12, no. 11 (2022). <a href="https://doi.org/10.3390/cryst12111586">https://doi.org/10.3390/cryst12111586</a>.
  ieee: 'F. Schmidt, A. L. Kozub, U. Gerstmann, W. G. Schmidt, and A. Schindlmayr,
    “A density-functional theory study of hole and defect-bound exciton polarons in
    lithium niobate,” <i>Crystals</i>, vol. 12, no. 11, Art. no. 1586, 2022, doi:
    <a href="https://doi.org/10.3390/cryst12111586">10.3390/cryst12111586</a>.'
  mla: Schmidt, Falko, et al. “A Density-Functional Theory Study of Hole and Defect-Bound
    Exciton Polarons in Lithium Niobate.” <i>Crystals</i>, vol. 12, no. 11, 1586,
    MDPI AG, 2022, doi:<a href="https://doi.org/10.3390/cryst12111586">10.3390/cryst12111586</a>.
  short: F. Schmidt, A.L. Kozub, U. Gerstmann, W.G. Schmidt, A. Schindlmayr, Crystals
    12 (2022).
date_created: 2023-04-20T13:52:44Z
date_updated: 2025-09-18T13:28:05Z
ddc:
- '530'
department:
- _id: '15'
- _id: '296'
- _id: '170'
- _id: '295'
- _id: '35'
- _id: '230'
- _id: '429'
- _id: '27'
doi: 10.3390/cryst12111586
external_id:
  isi:
  - '000895837200001'
file:
- access_level: open_access
  content_type: application/pdf
  creator: schindlm
  date_created: 2023-06-11T23:59:27Z
  date_updated: 2023-06-12T00:22:51Z
  description: Creative Commons Attribution 4.0 International Public License (CC BY
    4.0)
  file_id: '45570'
  file_name: crystals-12-01586-v2.pdf
  file_size: 1762554
  relation: main_file
  title: A density-functional theory study of hole and defect-bound exciton polarons
    in lithium niobate
file_date_updated: 2023-06-12T00:22:51Z
has_accepted_license: '1'
intvolume: '        12'
isi: '1'
issue: '11'
language:
- iso: eng
oa: '1'
project:
- _id: '53'
  name: 'TRR 142: TRR 142'
- _id: '54'
  name: 'TRR 142 - A: TRR 142 - Project Area A'
- _id: '55'
  name: 'TRR 142 - B: TRR 142 - Project Area B'
- _id: '69'
  name: 'TRR 142 - B04: TRR 142 - Subproject B04'
- _id: '168'
  name: 'TRR 142 - B07: TRR 142 - Subproject B07'
- _id: '166'
  name: 'TRR 142 - A11: TRR 142 - Subproject A11'
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Crystals
publication_identifier:
  eissn:
  - 2073-4352
publication_status: published
publisher: MDPI AG
quality_controlled: '1'
status: public
title: A density-functional theory study of hole and defect-bound exciton polarons
  in lithium niobate
type: journal_article
user_id: '16199'
volume: 12
year: '2022'
...
---
_id: '30288'
abstract:
- lang: eng
  text: Lithium niobate (LiNbO3), a material frequently used in optical applications,
    hosts different kinds of polarons that significantly affect many of its physical
    properties. In this study, a variety of electron polarons, namely free, bound,
    and bipolarons, are analyzed using first-principles calculations. We perform a
    full structural optimization based on density-functional theory for selected intrinsic
    defects with special attention to the role of symmetry-breaking distortions that
    lower the total energy. The cations hosting the various polarons relax to a different
    degree, with a larger relaxation corresponding to a larger gap between the defect
    level and the conduction-band edge. The projected density of states reveals that
    the polaron states are formerly empty Nb 4d states lowered into the band gap.
    Optical absorption spectra are derived within the independent-particle approximation,
    corrected by the GW approximation that yields a wider band gap and by including
    excitonic effects within the Bethe-Salpeter equation. Comparing the calculated
    spectra with the density of states, we find that the defect peak observed in the
    optical absorption stems from transitions between the defect level and a continuum
    of empty Nb 4d states. Signatures of polarons are further analyzed in the reflectivity
    and other experimentally measurable optical coefficients.
author:
- first_name: Falko
  full_name: Schmidt, Falko
  id: '35251'
  last_name: Schmidt
  orcid: 0000-0002-5071-5528
- first_name: Agnieszka L.
  full_name: Kozub, Agnieszka L.
  id: '77566'
  last_name: Kozub
  orcid: https://orcid.org/0000-0001-6584-0201
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
- first_name: Arno
  full_name: Schindlmayr, Arno
  id: '458'
  last_name: Schindlmayr
  orcid: 0000-0002-4855-071X
citation:
  ama: 'Schmidt F, Kozub AL, Gerstmann U, Schmidt WG, Schindlmayr A. Electron polarons
    in lithium niobate: Charge localization, lattice deformation, and optical response.
    In: Corradi G, Kovács L, eds. <i>New Trends in Lithium Niobate: From Bulk to Nanocrystals</i>.
    MDPI; 2022:231-248. doi:<a href="https://doi.org/10.3390/books978-3-0365-3339-1">10.3390/books978-3-0365-3339-1</a>'
  apa: 'Schmidt, F., Kozub, A. L., Gerstmann, U., Schmidt, W. G., &#38; Schindlmayr,
    A. (2022). Electron polarons in lithium niobate: Charge localization, lattice
    deformation, and optical response. In G. Corradi &#38; L. Kovács (Eds.), <i>New
    Trends in Lithium Niobate: From Bulk to Nanocrystals</i> (pp. 231–248). MDPI.
    <a href="https://doi.org/10.3390/books978-3-0365-3339-1">https://doi.org/10.3390/books978-3-0365-3339-1</a>'
  bibtex: '@inbook{Schmidt_Kozub_Gerstmann_Schmidt_Schindlmayr_2022, place={Basel},
    title={Electron polarons in lithium niobate: Charge localization, lattice deformation,
    and optical response}, DOI={<a href="https://doi.org/10.3390/books978-3-0365-3339-1">10.3390/books978-3-0365-3339-1</a>},
    booktitle={New Trends in Lithium Niobate: From Bulk to Nanocrystals}, publisher={MDPI},
    author={Schmidt, Falko and Kozub, Agnieszka L. and Gerstmann, Uwe and Schmidt,
    Wolf Gero and Schindlmayr, Arno}, editor={Corradi, Gábor and Kovács, László},
    year={2022}, pages={231–248} }'
  chicago: 'Schmidt, Falko, Agnieszka L. Kozub, Uwe Gerstmann, Wolf Gero Schmidt,
    and Arno Schindlmayr. “Electron Polarons in Lithium Niobate: Charge Localization,
    Lattice Deformation, and Optical Response.” In <i>New Trends in Lithium Niobate:
    From Bulk to Nanocrystals</i>, edited by Gábor Corradi and László Kovács, 231–48.
    Basel: MDPI, 2022. <a href="https://doi.org/10.3390/books978-3-0365-3339-1">https://doi.org/10.3390/books978-3-0365-3339-1</a>.'
  ieee: 'F. Schmidt, A. L. Kozub, U. Gerstmann, W. G. Schmidt, and A. Schindlmayr,
    “Electron polarons in lithium niobate: Charge localization, lattice deformation,
    and optical response,” in <i>New Trends in Lithium Niobate: From Bulk to Nanocrystals</i>,
    G. Corradi and L. Kovács, Eds. Basel: MDPI, 2022, pp. 231–248.'
  mla: 'Schmidt, Falko, et al. “Electron Polarons in Lithium Niobate: Charge Localization,
    Lattice Deformation, and Optical Response.” <i>New Trends in Lithium Niobate:
    From Bulk to Nanocrystals</i>, edited by Gábor Corradi and László Kovács, MDPI,
    2022, pp. 231–48, doi:<a href="https://doi.org/10.3390/books978-3-0365-3339-1">10.3390/books978-3-0365-3339-1</a>.'
  short: 'F. Schmidt, A.L. Kozub, U. Gerstmann, W.G. Schmidt, A. Schindlmayr, in:
    G. Corradi, L. Kovács (Eds.), New Trends in Lithium Niobate: From Bulk to Nanocrystals,
    MDPI, Basel, 2022, pp. 231–248.'
date_created: 2022-03-13T15:28:47Z
date_updated: 2025-12-05T14:00:04Z
ddc:
- '530'
department:
- _id: '296'
- _id: '230'
- _id: '429'
- _id: '295'
- _id: '15'
- _id: '170'
- _id: '35'
- _id: '790'
doi: 10.3390/books978-3-0365-3339-1
editor:
- first_name: Gábor
  full_name: Corradi, Gábor
  last_name: Corradi
- first_name: László
  full_name: Kovács, László
  last_name: Kovács
language:
- iso: eng
page: 231-248
place: Basel
project:
- _id: '53'
  name: 'TRR 142: TRR 142'
- _id: '55'
  name: 'TRR 142 - B: TRR 142 - Project Area B'
- _id: '69'
  name: 'TRR 142 - B4: TRR 142 - Subproject B4'
- _id: '54'
  name: 'TRR 142 - A: TRR 142 - Project Area A'
- _id: '166'
  name: 'TRR 142 - A11: TRR 142 - Subproject A11'
- _id: '168'
  name: 'TRR 142 - B07: TRR 142 - Subproject B07'
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
- _id: '53'
  name: 'TRR 142: Maßgeschneiderte nichtlineare Photonik: Von grundlegenden Konzepten
    zu funktionellen Strukturen'
publication: 'New Trends in Lithium Niobate: From Bulk to Nanocrystals'
publication_identifier:
  eisbn:
  - 978-3-0365-3339-1
  isbn:
  - 978-3-0365-3340-7
publication_status: published
publisher: MDPI
quality_controlled: '1'
status: public
title: 'Electron polarons in lithium niobate: Charge localization, lattice deformation,
  and optical response'
type: book_chapter
user_id: '16199'
year: '2022'
...
---
_id: '21946'
abstract:
- lang: eng
  text: Lithium niobate (LiNbO3), a material frequently used in optical applications,
    hosts different kinds of polarons that significantly affect many of its physical
    properties. In this study, a variety of electron polarons, namely free, bound,
    and bipolarons, are analyzed using first-principles calculations. We perform a
    full structural optimization based on density-functional theory for selected intrinsic
    defects with special attention to the role of symmetry-breaking distortions that
    lower the total energy. The cations hosting the various polarons relax to a different
    degree, with a larger relaxation corresponding to a larger gap between the defect
    level and the conduction-band edge. The projected density of states reveals that
    the polaron states are formerly empty Nb 4d states lowered into the band gap.
    Optical absorption spectra are derived within the independent-particle approximation,
    corrected by the GW approximation that yields a wider band gap and by including
    excitonic effects within the Bethe-Salpeter equation. Comparing the calculated
    spectra with the density of states, we find that the defect peak observed in the
    optical absorption stems from transitions between the defect level and a continuum
    of empty Nb 4d states. Signatures of polarons are further analyzed in the reflectivity
    and other experimentally measurable optical coefficients.
article_type: original
author:
- first_name: Falko
  full_name: Schmidt, Falko
  id: '35251'
  last_name: Schmidt
  orcid: 0000-0002-5071-5528
- first_name: Agnieszka L.
  full_name: Kozub, Agnieszka L.
  id: '77566'
  last_name: Kozub
  orcid: https://orcid.org/0000-0001-6584-0201
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
- first_name: Arno
  full_name: Schindlmayr, Arno
  id: '458'
  last_name: Schindlmayr
  orcid: 0000-0002-4855-071X
citation:
  ama: 'Schmidt F, Kozub AL, Gerstmann U, Schmidt WG, Schindlmayr A. Electron polarons
    in lithium niobate: Charge localization, lattice deformation, and optical response.
    <i>Crystals</i>. 2021;11:542. doi:<a href="https://doi.org/10.3390/cryst11050542">10.3390/cryst11050542</a>'
  apa: 'Schmidt, F., Kozub, A. L., Gerstmann, U., Schmidt, W. G., &#38; Schindlmayr,
    A. (2021). Electron polarons in lithium niobate: Charge localization, lattice
    deformation, and optical response. <i>Crystals</i>, <i>11</i>, 542. <a href="https://doi.org/10.3390/cryst11050542">https://doi.org/10.3390/cryst11050542</a>'
  bibtex: '@article{Schmidt_Kozub_Gerstmann_Schmidt_Schindlmayr_2021, title={Electron
    polarons in lithium niobate: Charge localization, lattice deformation, and optical
    response}, volume={11}, DOI={<a href="https://doi.org/10.3390/cryst11050542">10.3390/cryst11050542</a>},
    journal={Crystals}, publisher={MDPI}, author={Schmidt, Falko and Kozub, Agnieszka
    L. and Gerstmann, Uwe and Schmidt, Wolf Gero and Schindlmayr, Arno}, year={2021},
    pages={542} }'
  chicago: 'Schmidt, Falko, Agnieszka L. Kozub, Uwe Gerstmann, Wolf Gero Schmidt,
    and Arno Schindlmayr. “Electron Polarons in Lithium Niobate: Charge Localization,
    Lattice Deformation, and Optical Response.” <i>Crystals</i> 11 (2021): 542. <a
    href="https://doi.org/10.3390/cryst11050542">https://doi.org/10.3390/cryst11050542</a>.'
  ieee: 'F. Schmidt, A. L. Kozub, U. Gerstmann, W. G. Schmidt, and A. Schindlmayr,
    “Electron polarons in lithium niobate: Charge localization, lattice deformation,
    and optical response,” <i>Crystals</i>, vol. 11, p. 542, 2021, doi: <a href="https://doi.org/10.3390/cryst11050542">10.3390/cryst11050542</a>.'
  mla: 'Schmidt, Falko, et al. “Electron Polarons in Lithium Niobate: Charge Localization,
    Lattice Deformation, and Optical Response.” <i>Crystals</i>, vol. 11, MDPI, 2021,
    p. 542, doi:<a href="https://doi.org/10.3390/cryst11050542">10.3390/cryst11050542</a>.'
  short: F. Schmidt, A.L. Kozub, U. Gerstmann, W.G. Schmidt, A. Schindlmayr, Crystals
    11 (2021) 542.
date_created: 2021-05-03T09:36:13Z
date_updated: 2023-04-21T11:20:15Z
ddc:
- '530'
department:
- _id: '296'
- _id: '230'
- _id: '429'
- _id: '295'
- _id: '15'
- _id: '170'
- _id: '35'
- _id: '790'
doi: 10.3390/cryst11050542
external_id:
  isi:
  - '000653822700001'
file:
- access_level: open_access
  content_type: application/pdf
  creator: schindlm
  date_created: 2021-05-13T16:47:11Z
  date_updated: 2021-05-13T16:51:41Z
  description: Creative Commons Attribution 4.0 International Public License (CC BY
    4.0)
  file_id: '22163'
  file_name: crystals-11-00542.pdf
  file_size: 3042827
  relation: main_file
  title: 'Electron polarons in lithium niobate: Charge localization, lattice deformation,
    and optical response'
file_date_updated: 2021-05-13T16:51:41Z
funded_apc: '1'
has_accepted_license: '1'
intvolume: '        11'
isi: '1'
language:
- iso: eng
oa: '1'
page: '542'
project:
- _id: '53'
  name: TRR 142
- _id: '55'
  name: TRR 142 - Project Area B
- _id: '69'
  name: TRR 142 - Subproject B4
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Crystals
publication_identifier:
  eissn:
  - 2073-4352
publication_status: published
publisher: MDPI
quality_controlled: '1'
status: public
title: 'Electron polarons in lithium niobate: Charge localization, lattice deformation,
  and optical response'
type: journal_article
user_id: '171'
volume: 11
year: '2021'
...
---
_id: '23418'
abstract:
- lang: eng
  text: Density-functional theory within a Berry-phase formulation of the dynamical
    polarization is used to determine the second-order susceptibility χ(2) of lithium
    niobate (LiNbO3). Defect trapped polarons and bipolarons are found to strongly
    enhance the nonlinear susceptibility of the material, in particular if localized
    at NbV–VLi defect pairs. This is essentially a consequence of the polaronic excitation
    resulting in relaxation-induced gap states. The occupation of these levels leads
    to strongly enhanced χ(2) coefficients and allows for the spatial and transient
    modification of the second-harmonic generation of macroscopic samples.
article_type: original
author:
- first_name: Agnieszka L.
  full_name: Kozub, Agnieszka L.
  id: '77566'
  last_name: Kozub
  orcid: https://orcid.org/0000-0001-6584-0201
- first_name: Arno
  full_name: Schindlmayr, Arno
  id: '458'
  last_name: Schindlmayr
  orcid: 0000-0002-4855-071X
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
citation:
  ama: Kozub AL, Schindlmayr A, Gerstmann U, Schmidt WG. Polaronic enhancement of
    second-harmonic generation in lithium niobate. <i>Physical Review B</i>. 2021;104:174110.
    doi:<a href="https://doi.org/10.1103/PhysRevB.104.174110">10.1103/PhysRevB.104.174110</a>
  apa: Kozub, A. L., Schindlmayr, A., Gerstmann, U., &#38; Schmidt, W. G. (2021).
    Polaronic enhancement of second-harmonic generation in lithium niobate. <i>Physical
    Review B</i>, <i>104</i>, 174110. <a href="https://doi.org/10.1103/PhysRevB.104.174110">https://doi.org/10.1103/PhysRevB.104.174110</a>
  bibtex: '@article{Kozub_Schindlmayr_Gerstmann_Schmidt_2021, title={Polaronic enhancement
    of second-harmonic generation in lithium niobate}, volume={104}, DOI={<a href="https://doi.org/10.1103/PhysRevB.104.174110">10.1103/PhysRevB.104.174110</a>},
    journal={Physical Review B}, publisher={American Physical Society}, author={Kozub,
    Agnieszka L. and Schindlmayr, Arno and Gerstmann, Uwe and Schmidt, Wolf Gero},
    year={2021}, pages={174110} }'
  chicago: 'Kozub, Agnieszka L., Arno Schindlmayr, Uwe Gerstmann, and Wolf Gero Schmidt.
    “Polaronic Enhancement of Second-Harmonic Generation in Lithium Niobate.” <i>Physical
    Review B</i> 104 (2021): 174110. <a href="https://doi.org/10.1103/PhysRevB.104.174110">https://doi.org/10.1103/PhysRevB.104.174110</a>.'
  ieee: 'A. L. Kozub, A. Schindlmayr, U. Gerstmann, and W. G. Schmidt, “Polaronic
    enhancement of second-harmonic generation in lithium niobate,” <i>Physical Review
    B</i>, vol. 104, p. 174110, 2021, doi: <a href="https://doi.org/10.1103/PhysRevB.104.174110">10.1103/PhysRevB.104.174110</a>.'
  mla: Kozub, Agnieszka L., et al. “Polaronic Enhancement of Second-Harmonic Generation
    in Lithium Niobate.” <i>Physical Review B</i>, vol. 104, American Physical Society,
    2021, p. 174110, doi:<a href="https://doi.org/10.1103/PhysRevB.104.174110">10.1103/PhysRevB.104.174110</a>.
  short: A.L. Kozub, A. Schindlmayr, U. Gerstmann, W.G. Schmidt, Physical Review B
    104 (2021) 174110.
date_created: 2021-08-16T19:09:46Z
date_updated: 2023-04-21T11:15:30Z
ddc:
- '530'
department:
- _id: '296'
- _id: '230'
- _id: '429'
- _id: '295'
- _id: '15'
- _id: '170'
- _id: '790'
doi: 10.1103/PhysRevB.104.174110
external_id:
  arxiv:
  - '2106.01145'
  isi:
  - '000720931400007'
file:
- access_level: open_access
  content_type: application/pdf
  creator: schindlm
  date_created: 2021-11-18T20:49:19Z
  date_updated: 2021-11-18T20:49:19Z
  description: © 2021 American Physical Society
  file_id: '27577'
  file_name: PhysRevB.104.174110.pdf
  file_size: 804012
  relation: main_file
  title: Polaronic enhancement of second-harmonic generation in lithium niobate
file_date_updated: 2021-11-18T20:49:19Z
has_accepted_license: '1'
intvolume: '       104'
isi: '1'
language:
- iso: eng
oa: '1'
page: '174110'
project:
- _id: '53'
  name: TRR 142
- _id: '55'
  name: TRR 142 - Project Area B
- _id: '69'
  name: TRR 142 - Subproject B4
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Physical Review B
publication_identifier:
  eissn:
  - 2469-9969
  issn:
  - 2469-9950
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: Polaronic enhancement of second-harmonic generation in lithium niobate
type: journal_article
user_id: '171'
volume: 104
year: '2021'
...
---
_id: '19190'
abstract:
- lang: eng
  text: "Polarons in dielectric crystals play a crucial role for applications in integrated
    electronics and optoelectronics. In this work, we use density-functional theory
    and Green's function methods to explore the microscopic structure and spectroscopic
    signatures of electron polarons in lithium niobate (LiNbO3). Total-energy calculations
    and the comparison of calculated electron paramagnetic resonance data with available
    measurements reveal the formation of bound \r\npolarons at Nb_Li antisite defects
    with a quasi-Jahn-Teller distorted, tilted configuration. The defect-formation
    energies further indicate that (bi)polarons may form not only at \r\nNb_Li antisites
    but also at structures where the antisite Nb atom moves into a neighboring empty
    oxygen octahedron. Based on these structure models, and on the calculated charge-transition
    levels and potential-energy barriers, we propose two mechanisms for the optical
    and thermal splitting of bipolarons, which provide a natural explanation for the
    reported two-path recombination of bipolarons. Optical-response calculations based
    on the Bethe-Salpeter equation, in combination with available experimental data
    and new measurements of the optical absorption spectrum, further corroborate the
    geometries proposed here for free and defect-bound (bi)polarons."
article_number: '043002'
article_type: original
author:
- first_name: Falko
  full_name: Schmidt, Falko
  id: '35251'
  last_name: Schmidt
  orcid: 0000-0002-5071-5528
- first_name: Agnieszka L.
  full_name: Kozub, Agnieszka L.
  id: '77566'
  last_name: Kozub
  orcid: https://orcid.org/0000-0001-6584-0201
- first_name: Timur
  full_name: Biktagirov, Timur
  id: '65612'
  last_name: Biktagirov
- first_name: Christof
  full_name: Eigner, Christof
  id: '13244'
  last_name: Eigner
  orcid: https://orcid.org/0000-0002-5693-3083
- first_name: Christine
  full_name: Silberhorn, Christine
  id: '26263'
  last_name: Silberhorn
- first_name: Arno
  full_name: Schindlmayr, Arno
  id: '458'
  last_name: Schindlmayr
  orcid: 0000-0002-4855-071X
- first_name: Wolf Gero
  full_name: Schmidt, Wolf Gero
  id: '468'
  last_name: Schmidt
  orcid: 0000-0002-2717-5076
- first_name: Uwe
  full_name: Gerstmann, Uwe
  id: '171'
  last_name: Gerstmann
  orcid: 0000-0002-4476-223X
citation:
  ama: 'Schmidt F, Kozub AL, Biktagirov T, et al. Free and defect-bound (bi)polarons
    in LiNbO3: Atomic structure and spectroscopic signatures from ab initio calculations.
    <i>Physical Review Research</i>. 2020;2(4). doi:<a href="https://doi.org/10.1103/PhysRevResearch.2.043002">10.1103/PhysRevResearch.2.043002</a>'
  apa: 'Schmidt, F., Kozub, A. L., Biktagirov, T., Eigner, C., Silberhorn, C., Schindlmayr,
    A., Schmidt, W. G., &#38; Gerstmann, U. (2020). Free and defect-bound (bi)polarons
    in LiNbO3: Atomic structure and spectroscopic signatures from ab initio calculations.
    <i>Physical Review Research</i>, <i>2</i>(4), Article 043002. <a href="https://doi.org/10.1103/PhysRevResearch.2.043002">https://doi.org/10.1103/PhysRevResearch.2.043002</a>'
  bibtex: '@article{Schmidt_Kozub_Biktagirov_Eigner_Silberhorn_Schindlmayr_Schmidt_Gerstmann_2020,
    title={Free and defect-bound (bi)polarons in LiNbO3: Atomic structure and spectroscopic
    signatures from ab initio calculations}, volume={2}, DOI={<a href="https://doi.org/10.1103/PhysRevResearch.2.043002">10.1103/PhysRevResearch.2.043002</a>},
    number={4043002}, journal={Physical Review Research}, publisher={American Physical
    Society}, author={Schmidt, Falko and Kozub, Agnieszka L. and Biktagirov, Timur
    and Eigner, Christof and Silberhorn, Christine and Schindlmayr, Arno and Schmidt,
    Wolf Gero and Gerstmann, Uwe}, year={2020} }'
  chicago: 'Schmidt, Falko, Agnieszka L. Kozub, Timur Biktagirov, Christof Eigner,
    Christine Silberhorn, Arno Schindlmayr, Wolf Gero Schmidt, and Uwe Gerstmann.
    “Free and Defect-Bound (Bi)Polarons in LiNbO3: Atomic Structure and Spectroscopic
    Signatures from Ab Initio Calculations.” <i>Physical Review Research</i> 2, no.
    4 (2020). <a href="https://doi.org/10.1103/PhysRevResearch.2.043002">https://doi.org/10.1103/PhysRevResearch.2.043002</a>.'
  ieee: 'F. Schmidt <i>et al.</i>, “Free and defect-bound (bi)polarons in LiNbO3:
    Atomic structure and spectroscopic signatures from ab initio calculations,” <i>Physical
    Review Research</i>, vol. 2, no. 4, Art. no. 043002, 2020, doi: <a href="https://doi.org/10.1103/PhysRevResearch.2.043002">10.1103/PhysRevResearch.2.043002</a>.'
  mla: 'Schmidt, Falko, et al. “Free and Defect-Bound (Bi)Polarons in LiNbO3: Atomic
    Structure and Spectroscopic Signatures from Ab Initio Calculations.” <i>Physical
    Review Research</i>, vol. 2, no. 4, 043002, American Physical Society, 2020, doi:<a
    href="https://doi.org/10.1103/PhysRevResearch.2.043002">10.1103/PhysRevResearch.2.043002</a>.'
  short: F. Schmidt, A.L. Kozub, T. Biktagirov, C. Eigner, C. Silberhorn, A. Schindlmayr,
    W.G. Schmidt, U. Gerstmann, Physical Review Research 2 (2020).
date_created: 2020-09-09T09:35:21Z
date_updated: 2023-04-20T16:06:21Z
ddc:
- '530'
department:
- _id: '296'
- _id: '230'
- _id: '429'
- _id: '295'
- _id: '288'
- _id: '15'
- _id: '170'
- _id: '35'
- _id: '790'
doi: 10.1103/PhysRevResearch.2.043002
external_id:
  isi:
  - '000604206300002'
file:
- access_level: open_access
  content_type: application/pdf
  creator: schindlm
  date_created: 2020-10-02T07:27:38Z
  date_updated: 2020-10-02T07:37:24Z
  description: Creative Commons Attribution 4.0 International Public License (CC BY
    4.0)
  file_id: '19843'
  file_name: PhysRevResearch.2.043002.pdf
  file_size: 1955183
  relation: main_file
  title: 'Free and defect-bound (bi)polarons in LiNbO3: Atomic structure and spectroscopic
    signatures from ab initio calculations'
file_date_updated: 2020-10-02T07:37:24Z
has_accepted_license: '1'
intvolume: '         2'
isi: '1'
issue: '4'
language:
- iso: eng
oa: '1'
project:
- _id: '53'
  name: TRR 142
- _id: '55'
  name: TRR 142 - Project Area B
- _id: '69'
  name: TRR 142 - Subproject B4
- _id: '52'
  name: Computing Resources Provided by the Paderborn Center for Parallel Computing
- _id: '52'
  name: 'PC2: Computing Resources Provided by the Paderborn Center for Parallel Computing'
publication: Physical Review Research
publication_identifier:
  eissn:
  - 2643-1564
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
status: public
title: 'Free and defect-bound (bi)polarons in LiNbO3: Atomic structure and spectroscopic
  signatures from ab initio calculations'
type: journal_article
user_id: '16199'
volume: 2
year: '2020'
...