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Title: Competing pairing interactions responsible for the large upper critical field in a stoichiometric iron-based superconductor CaKFe4As4

Abstract

The upper critical field of multiband superconductors is an important quantity that can reveal details about the nature of the superconducting pairing. Here in this paper we experimentally map out the complete upper-critical-field phase diagram of a stoichiometric superconductor, CaKFe4 As4, up to 90 T for different orientations of the magnetic field and at temperatures down to 4.2 K . The upper critical fields are extremely large, reaching values close to ~ 3Tc at the lowest temperature, and the anisotropy decreases dramatically with temperature, leading to essentially isotropic superconductivity at 4.2 K . We find that the temperature dependence of the upper critical field can be well described by a two-band model in the clean limit with band-coupling parameters favoring intraband over interband interactions. The large Pauli paramagnetic effects together with the presence of the shallow bands is consistent with the stabilization of an FFLO state at low temperatures in this clean superconductor.

Authors:
ORCiD logo [1];  [2]; ORCiD logo [1];  [3];  [3];  [1]; ORCiD logo [1]
  1. Univ. of Oxford (United Kingdom). Clarendon Lab., Dept. of Physics
  2. Lab. National des Champs Magnétiques Intenses (LNCMI), Toulouse (France). CNRS-UJF-UPS-INSA
  3. Ames Lab., and Iowa State Univ., Ames, IA (United States). Dept. of Physics and Astronomy
Publication Date:
Research Org.:
Ames Lab., Ames, IA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; Engineering and Physical Sciences Research Council (EPSRC); Oxford University; Gordon and Betty Moore Foundations (GBMF); European Magnetic Field Laboratory (EMFL); USDOE
OSTI Identifier:
1615930
Alternate Identifier(s):
OSTI ID: 1632920
Report Number(s):
IS-J-10,199
Journal ID: ISSN 2469-9950; PRBMDO
Grant/Contract Number:  
EP/I004475/1; EP/EP/I017836/1; EP/N01085X/1; EP/M020517/1; AC02-07CH11358; GBMF4411
Resource Type:
Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 101; Journal Issue: 13; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society (APS)
Country of Publication:
United States
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Bristow, Matthew, Knafo, William, Reiss, Pascal, Meier, William, Canfield, Paul C., Blundell, Stephen J., and Coldea, Amalia I. Competing pairing interactions responsible for the large upper critical field in a stoichiometric iron-based superconductor CaKFe4As4. United States: N. p., 2020. Web. doi:10.1103/PhysRevB.101.134502.
Bristow, Matthew, Knafo, William, Reiss, Pascal, Meier, William, Canfield, Paul C., Blundell, Stephen J., & Coldea, Amalia I. Competing pairing interactions responsible for the large upper critical field in a stoichiometric iron-based superconductor CaKFe4As4. United States. doi:https://doi.org/10.1103/PhysRevB.101.134502
Bristow, Matthew, Knafo, William, Reiss, Pascal, Meier, William, Canfield, Paul C., Blundell, Stephen J., and Coldea, Amalia I. Tue . "Competing pairing interactions responsible for the large upper critical field in a stoichiometric iron-based superconductor CaKFe4As4". United States. doi:https://doi.org/10.1103/PhysRevB.101.134502. https://www.osti.gov/servlets/purl/1615930.
@article{osti_1615930,
title = {Competing pairing interactions responsible for the large upper critical field in a stoichiometric iron-based superconductor CaKFe4As4},
author = {Bristow, Matthew and Knafo, William and Reiss, Pascal and Meier, William and Canfield, Paul C. and Blundell, Stephen J. and Coldea, Amalia I.},
abstractNote = {The upper critical field of multiband superconductors is an important quantity that can reveal details about the nature of the superconducting pairing. Here in this paper we experimentally map out the complete upper-critical-field phase diagram of a stoichiometric superconductor, CaKFe4 As4, up to 90 T for different orientations of the magnetic field and at temperatures down to 4.2 K . The upper critical fields are extremely large, reaching values close to ~ 3Tc at the lowest temperature, and the anisotropy decreases dramatically with temperature, leading to essentially isotropic superconductivity at 4.2 K . We find that the temperature dependence of the upper critical field can be well described by a two-band model in the clean limit with band-coupling parameters favoring intraband over interband interactions. The large Pauli paramagnetic effects together with the presence of the shallow bands is consistent with the stabilization of an FFLO state at low temperatures in this clean superconductor.},
doi = {10.1103/PhysRevB.101.134502},
journal = {Physical Review B},
number = 13,
volume = 101,
place = {United States},
year = {2020},
month = {4}
}

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Works referenced in this record:

Quantum FFLO State in Clean Layered Superconductors
journal, May 2019


Anisotropic thermodynamic and transport properties of single-crystalline CaKFe 4 As 4
journal, August 2016


Disorder-induced transition between s ± and s + + states in two-band superconductors
journal, November 2011


Fulde-Ferrell Effect in Type-II Superconductors
journal, May 1966


Evidence for dominant Pauli paramagnetic effect in the upper critical field of single-crystalline FeTe 0.6 Se 0.4
journal, May 2010


In-plane magnetic penetration depth of superconducting CaKFe 4 As 4
journal, April 2018


Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . III. Electron Spin and Spin-Orbit Effects
journal, July 1966


High- T c superconductivity in CaKFe 4 As 4 in absence of nematic fluctuations
journal, October 2018


Coexistence of superconductivity and magnetism in CaK ( Fe 1 x Ni x ) 4 As 4 as probed by 57 Fe Mössbauer spectroscopy
journal, October 2018


Effect of Ni doping on vortex pinning in CaK ( F e 1 − x N i x ) 4 A s 4 single crystals
journal, August 2019


New-Structure-Type Fe-Based Superconductors: Ca A Fe 4 As 4 ( A = K, Rb, Cs) and Sr A Fe 4 As 4 ( A = Rb, Cs)
journal, March 2016

  • Iyo, Akira; Kawashima, Kenji; Kinjo, Tatsuya
  • Journal of the American Chemical Society, Vol. 138, Issue 10
  • DOI: 10.1021/jacs.5b12571

Unique defect structure and advantageous vortex pinning properties in superconducting CaKFe4As4
journal, June 2019


Nearly isotropic superconductivity in (Ba,K)Fe2As2
journal, January 2009

  • Yuan, H. Q.; Singleton, J.; Balakirev, F. F.
  • Nature, Vol. 457, Issue 7229
  • DOI: 10.1038/nature07676

Upper critical field in a stoichiometric iron-based superconductor, CaKFe4As4
dataset, January 2020


Specific heat of MgB 2 in a one- and a two-band model from first-principles calculations
journal, January 2002

  • Golubov, A. A.; Kortus, J.; Dolgov, O. V.
  • Journal of Physics: Condensed Matter, Vol. 14, Issue 6
  • DOI: 10.1088/0953-8984/14/6/320

Electronic Properties and Fermi Surface for New Layered High-Temperature Superconductors CaAFe4As4 (A = K, Rb, and Cs): FLAPW-GGA Calculations
journal, November 2017

  • Suetin, D. V.; Shein, I. R.
  • Journal of Superconductivity and Novel Magnetism, Vol. 31, Issue 6
  • DOI: 10.1007/s10948-017-4404-y

Inversion of the upper critical field anisotropy in FeTeS films
journal, March 2014


57 Fe Mössbauer study of stoichiometric iron-based superconductor CaKFe 4 As 4 : a comparison to KFe 2 As 2 and CaFe 2 As 2
journal, July 2017


Magnetic fluctuations and superconducting properties of CaKFe 4 As 4 studied by As 75 NMR
journal, September 2017


Evidence for Anisotropic Vortex Dynamics and Pauli Limitation in the Upper Critical Field of FeSe 1- x Te x
journal, May 2010

  • Braithwaite, Daniel; Lapertot, Gérard; Knafo, William
  • Journal of the Physical Society of Japan, Vol. 79, Issue 5
  • DOI: 10.1143/JPSJ.79.053703

Anisotropic fluctuations and quasiparticle excitations in FeSe 0.5 Te 0.5
journal, September 2010


Orbital and spin effects for the upper critical field in As-deficient disordered Fe pnictide superconductors
journal, July 2009


Hedgehog Spin-Vortex Crystal Antiferromagnetic Quantum Criticality in CaK ( Fe 1 x Ni x ) 4 As 4 Revealed by NMR
journal, September 2018


Evidence for superconducting gap nodes in the zone-centered hole bands of KFe 2 As 2 from magnetic penetration-depth measurements
journal, July 2010


Iron-based superconductors at high magnetic fields
journal, September 2011


Significant enhancement of upper critical fields by doping and strain in iron-based superconductors
journal, November 2011


Electronic properties, low-energy Hamiltonian, and superconducting instabilities in CaKFe 4 As 4
journal, September 2017


Temperature and Purity Dependence of the Superconducting Critical Field, H c 2 . II
journal, July 1966


Anisotropy of the Upper Critical Field in a Co-Doped BaFe 2 As 2 Single Crystal
journal, August 2009

  • Kano, Mika; Kohama, Yoshimitsu; Graf, David
  • Journal of the Physical Society of Japan, Vol. 78, Issue 8
  • DOI: 10.1143/JPSJ.78.084719

Gap symmetry and structure of Fe-based superconductors
journal, October 2011


Enhancement of the Superconducting Gap by Nesting in CaKFe 4 As 4 : A New High Temperature Superconductor
journal, December 2016


Orbital-Fluctuation-Mediated Superconductivity in Iron Pnictides: Analysis of the Five-Orbital Hubbard-Holstein Model
journal, April 2010


Spin Resonance in the New-Structure-Type Iron-Based Superconductor CaKFe 4 As 4
journal, September 2017

  • Iida, Kazuki; Ishikado, Motoyuki; Nagai, Yuki
  • Journal of the Physical Society of Japan, Vol. 86, Issue 9
  • DOI: 10.7566/JPSJ.86.093703

Influence of multiband sign-changing superconductivity on vortex cores and vortex pinning in stoichiometric high- T c   CaKFe 4 As 4
journal, April 2018