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Title: Microscopic origin of Cooper pairing in the iron-based superconductor Ba1-xKxFe2As2

Abstract

Resolving the microscopic pairing mechanism and its experimental identification in unconventional superconductors is among the most vexing problems of contemporary condensed matter physics. We show that Raman spectroscopy provides an avenue towards this aim by probing the structure of the pairing interaction at play in an unconventional superconductor. As we study the spectra of the prototypical Fe-based superconductor Ba1-xKxFe2As2 for 0.22 ≤ x ≤ 0.70 in all symmetry channels, Raman spectroscopy allows us to distill the leading s-wave state. In addition, the spectra collected in the B1g symmetry channel reveal the existence of two collective modes which are indicative of the presence of two competing, yet sub-dominant, pairing tendencies of dx2-y2 symmetry type. A comprehensive functional Renormalization Group and random-phase approximation study on this compound confirms the presence of the two sub-leading channels, and consistently matches the experimental doping dependence of the related modes. In conclusion, the consistency between the experimental observations and the theoretical modeling suggests that spin fluctuations play a significant role in superconducting pairing.

Authors:
 [1];  [2];  [3];  [4];  [3];  [5];  [6];  [7];  [4];  [6];  [8];  [9];  [10];  [11];  [11];  [12];  [12];  [13]; ORCiD logo [14]
  1. Walther Meissner Institut, Garching (Germany); Technische Univ. Munchen, Garching (Germany); SLAC National Accelerator Lab., Menlo Park, CA (United States); TNG Technology Consulting GmbH, Unterfohring (Germany)
  2. Walther Meissner Institut, Garching (Germany); Technische Univ. Munchen, Garching (Germany); Intel Mobile Communications, Neubiberg (Germany)
  3. Walther Meissner Institut, Garching (Germany); Technische Univ. Munchen, Garching (Germany)
  4. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  5. Walther Meissner Institut, Garching (Germany); Technische Univ. Munchen, Garching (Germany); Univ. of Toledo, Toledo, OH (United States)
  6. Univ. of Wurzburg, Wurzburg (Germany)
  7. Stanford Univ., Stanford, CA (United States)
  8. SLAC National Accelerator Lab., Menlo Park, CA (United States)
  9. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., Stanford, CA (United States)
  10. Univ. of California, Santa Barbara, CA (United States)
  11. Univ. of Florida, Gainesville, FL (United States)
  12. Karlsruher Institut fur Technologie, Karlsruhe (Germany)
  13. Naning Univ., Nanjing (China)
  14. Walther Meissner Institut, Garching (Germany)
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE
OSTI Identifier:
1474720
Grant/Contract Number:  
AC05-00OR22725
Resource Type:
Accepted Manuscript
Journal Name:
npj Quantum Materials
Additional Journal Information:
Journal Volume: 3; Journal Issue: 1; Journal ID: ISSN 2397-4648
Publisher:
Nature Publishing Group
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Böhm, Thomas, Kretzschmar, Florian, Baum, Andreas, Rehm, Michael, Jost, Daniel, Ahangharnejhad, Ramez Hosseinian, Thomale, Ronny, Platt, Christian, Maier, Thomas A., Hanke, Werner, Moritz, Brian, Devereaux, Thomas P., Scalapino, Douglas J., Maiti, Saurabh, Hirschfeld, Peter J., Adelmann, Peter, Wolf, Thomas, Wen, Hai -Hu, and Hackl, Rudi. Microscopic origin of Cooper pairing in the iron-based superconductor Ba1-xKxFe2As2. United States: N. p., 2018. Web. doi:10.1038/s41535-018-0118-z.
Böhm, Thomas, Kretzschmar, Florian, Baum, Andreas, Rehm, Michael, Jost, Daniel, Ahangharnejhad, Ramez Hosseinian, Thomale, Ronny, Platt, Christian, Maier, Thomas A., Hanke, Werner, Moritz, Brian, Devereaux, Thomas P., Scalapino, Douglas J., Maiti, Saurabh, Hirschfeld, Peter J., Adelmann, Peter, Wolf, Thomas, Wen, Hai -Hu, & Hackl, Rudi. Microscopic origin of Cooper pairing in the iron-based superconductor Ba1-xKxFe2As2. United States. doi:https://doi.org/10.1038/s41535-018-0118-z
Böhm, Thomas, Kretzschmar, Florian, Baum, Andreas, Rehm, Michael, Jost, Daniel, Ahangharnejhad, Ramez Hosseinian, Thomale, Ronny, Platt, Christian, Maier, Thomas A., Hanke, Werner, Moritz, Brian, Devereaux, Thomas P., Scalapino, Douglas J., Maiti, Saurabh, Hirschfeld, Peter J., Adelmann, Peter, Wolf, Thomas, Wen, Hai -Hu, and Hackl, Rudi. Thu . "Microscopic origin of Cooper pairing in the iron-based superconductor Ba1-xKxFe2As2". United States. doi:https://doi.org/10.1038/s41535-018-0118-z. https://www.osti.gov/servlets/purl/1474720.
@article{osti_1474720,
title = {Microscopic origin of Cooper pairing in the iron-based superconductor Ba1-xKxFe2As2},
author = {Böhm, Thomas and Kretzschmar, Florian and Baum, Andreas and Rehm, Michael and Jost, Daniel and Ahangharnejhad, Ramez Hosseinian and Thomale, Ronny and Platt, Christian and Maier, Thomas A. and Hanke, Werner and Moritz, Brian and Devereaux, Thomas P. and Scalapino, Douglas J. and Maiti, Saurabh and Hirschfeld, Peter J. and Adelmann, Peter and Wolf, Thomas and Wen, Hai -Hu and Hackl, Rudi},
abstractNote = {Resolving the microscopic pairing mechanism and its experimental identification in unconventional superconductors is among the most vexing problems of contemporary condensed matter physics. We show that Raman spectroscopy provides an avenue towards this aim by probing the structure of the pairing interaction at play in an unconventional superconductor. As we study the spectra of the prototypical Fe-based superconductor Ba1-xKxFe2As2 for 0.22 ≤ x ≤ 0.70 in all symmetry channels, Raman spectroscopy allows us to distill the leading s-wave state. In addition, the spectra collected in the B1g symmetry channel reveal the existence of two collective modes which are indicative of the presence of two competing, yet sub-dominant, pairing tendencies of dx2-y2 symmetry type. A comprehensive functional Renormalization Group and random-phase approximation study on this compound confirms the presence of the two sub-leading channels, and consistently matches the experimental doping dependence of the related modes. In conclusion, the consistency between the experimental observations and the theoretical modeling suggests that spin fluctuations play a significant role in superconducting pairing.},
doi = {10.1038/s41535-018-0118-z},
journal = {npj Quantum Materials},
number = 1,
volume = 3,
place = {United States},
year = {2018},
month = {9}
}

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    Works referencing / citing this record:

    Classification and characterization of nonequilibrium Higgs modes in unconventional superconductors
    journal, January 2020


    Collective modes in pumped unconventional superconductors with competing ground states
    journal, October 2019