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

Journal Article · · npj Quantum Materials
 [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)
+ Show Author Affiliations

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.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1474720
Journal Information:
npj Quantum Materials, Journal Name: npj Quantum Materials Journal Issue: 1 Vol. 3; ISSN 2397-4648
Publisher:
Nature Publishing GroupCopyright Statement
Country of Publication:
United States
Language:
English

References (41)

Superconductivity and fluctuations in Ba 1- p K p Fe 2 As 2 and Ba(Fe 1- n Co n ) 2 As 2 : Superconductivity and fluctuations in Fe-based compounds journal August 2016
Using gap symmetry and structure to reveal the pairing mechanism in Fe-based superconductors journal January 2016
Iron-based superconductors: Current status of materials and pairing mechanism journal July 2015
High-temperature superconductivity in iron pnictides and chalcogenides journal March 2016
Critical spin fluctuations and the origin of nematic order in Ba(Fe1−xCox)2As2 journal January 2016
Functional renormalization group for multi-orbital Fermi surface instabilities journal November 2013
Superconducting properties of (Ba-K)Fe 2 As 2 single crystals disordered with fast neutron irradiation journal June 2014
Excitons and Plasmons in Superconductors journal February 1961
Theory of Raman scattering with final-state interaction in high- T c BCS superconductors: Collective modes journal May 1990
Momentum dependence of the superconducting gap in Ba 1 − x K x Fe 2 As 2 journal February 2009
Theory of Raman response of a superconductor with extended s -wave symmetry: Application to the iron pnictides journal June 2009
Pnictogen height as a possible switch between high- T c nodeless and low- T c nodal pairings in the iron-based superconductors journal June 2009
Collective d -wave exciton modes in the calculated Raman spectrum of Fe-based superconductors journal October 2009
Functional renormalization-group study of the doping dependence of pairing symmetry in the iron pnictide superconductors journal November 2009
Band- and momentum-dependent electron dynamics in superconducting Ba ( Fe 1 − x Co x ) 2 As 2 as seen via electronic Raman scattering journal November 2009
Phase diagram and gap anisotropy in iron-pnictide superconductors journal February 2010
Pinpointing gap minima in Ba ( Fe 0.94 Co 0.06 ) 2 As 2 via band-structure calculations and electronic Raman scattering journal November 2010
Universality of superconducting gaps in overdoped Ba 0.3 K 0.7 Fe 2 As 2 observed by angle-resolved photoemission spectroscopy journal January 2011
Transport properties and asymmetric scattering in Ba 1 − x K x Fe 2 As 2 single crystals journal November 2011
Possible nodal superconducting gap and Lifshitz transition in heavily hole-doped Ba 0.1 K 0.9 Fe 2 As 2 journal December 2013
Origin of nematic order in FeSe journal May 2015
Critical quadrupole fluctuations and collective modes in iron pnictide superconductors journal February 2016
Signature of the Leggett mode in the A 1 g Raman response: From MgB 2 to iron-based superconductors journal August 2016
Strong correlations, strong coupling, and s -wave superconductivity in hole-doped BaFe 2 As 2 single crystals journal November 2016
Superconductivity and electronic fluctuations in Ba 1 − x K x Fe 2 As 2 studied by Raman scattering journal February 2017
Unconventional Superconductivity with a Sign Reversal in the Order Parameter of LaFeAsO 1 − x F x journal July 2008
Superconductivity at 38 K in the Iron Arsenide ( Ba 1 − x K x ) Fe 2 As 2 journal September 2008
Exotic d -Wave Superconducting State of Strongly Hole-Doped K x Ba 1 − x Fe 2 As 2 journal September 2011
Raman-Scattering Detection of Nearly Degenerate s -Wave and d -Wave Pairing Channels in Iron-Based Ba 0.6 K 0.4 Fe 2 As 2 and Rb 0.8 Fe 1.6 Se 2 Superconductors journal May 2013
Nematic Susceptibility of Hole-Doped and Electron-Doped Ba F e 2 As 2 Iron-Based Superconductors from Shear Modulus Measurements journal January 2014
Nematic Resonance in the Raman Response of Iron-Based Superconductors journal January 2016
Probing the Pairing Interaction and Multiple Bardasis-Schrieffer Modes Using Raman Spectroscopy journal December 2016
Theory of Electronic Raman Scattering in Disordered Unconventional Superconductors journal May 1995
Inelastic light scattering from correlated electrons journal January 2007
Functional renormalization group approach to correlated fermion systems journal March 2012
Number-Phase Fluctuations in Two-Band Superconductors journal November 1966
Phase diagram and Gap anisotropy in Iron-Pnictide Superconductors text January 2009
Functional Renormalization Group for multi-orbital Fermi Surface Instabilities text January 2013
Using Gap Symmetry and Structure to Reveal the Pairing Mechanism in Fe-based Superconductors text January 2015
High Temperature Superconductivity in Iron Pnictides and Chalcogenides text January 2016
Inelastic Light Scattering From Correlated Electrons text January 2006

Cited By (3)

Classification and characterization of nonequilibrium Higgs modes in unconventional superconductors journal January 2020
Theory of ultrafast phenomena in photoexcited semiconductors journal August 2002
Collective modes in pumped unconventional superconductors with competing ground states journal October 2019

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