Unconventional Multi-gap Superconductivity and Antiferromagnetic Spin Fluctuations in New Iron-arsenide LaFe2As2 in Heavily Electron-doped Regime
arXiv:1909.01569 · doi:10.7566/JPSJ.88.113702
Abstract
We report 75As-NMR/NQR results on new iron-arsenide compounds (La0.5-xNa0.5+x)Fe2As2. The parent compound x=0 exhibits a stripe-type antiferromagnetic (AFM) order below T_N=130 K. The measurement of nuclear spin relaxation rate at hole-doped x=+0.3 and heavily electron-doped x=-0.5 revealed that the normal-state properties are dominated by AFM spin fluctuations (AFMSFs), which are more significant at x=+0.3 than at x=-0.5. Their superconducting (SC) phases are characterized by unconventional multi-gap SC state, where the smaller SC gaps are particularly weaken in common. The experimental results indicate the close relationship between the AFMSFs and the SC from the hole-doped state to heavily electron-doped state, which shed light on a unique SC phase emerged in the heavily electron-doped regime being formally equivalent to non-SC compound Ba(Fe0.5Co0.5)Fe2As2.
5 pages, 4 figures
References in corpus (39)
- Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
- Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsOF}
- Interface induced high temperature superconductivity in single unit-cell FeSe films on SrTiO3
- Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
- Phase Diagram and High Temperature Superconductivity at 65 K in Tuning Carrier Concentration of Single-Layer FeSe Films
- Heavily electron-doped electronic structure and isotropic superconducting gap in AxFe2Se2 (A=K,Cs)
- Orbital-driven nematicity in FeSe
- Comparison of Ab initio Low-Energy Models for LaFePO, LaFeAsO, BaFe2As2, LiFeAs, FeSe and FeTe: Electron Correlation and Covalency
- Contrasting Spin Dynamics Between Underdoped and Overdoped Ba(Fe[1-x]Co[x])2As2
- Two-dome structure in electron-doped iron arsenide superconductors
- Commensurate Itinerant Antiferromagnetism in BaFe2As2: 75As-NMR Studies on a Self-Flux Grown Single Crystal
- Unconventional superconductivity and antiferromagnetic quantum critical behavior in the isovalent-doped BaFe2(As1-xPx)2
- Common Electronic Origin of Superconductivity in (Li,Fe)OHFeSe Bulk Superconductor and Single-Layer FeSe/SrTiO3 Films
- Spin susceptibility, phase diagram, and quantum criticality in the electron-doped high Tc Superconductor Ba[Fe(1-x)Co(x)]2As2
- Importance of Fermi surface topology for high temperature superconductivity in electron-doped iron arsenic superconductors
- Bipartite magnetic parent phases in the iron-oxypnictide superconductor
- Renormalized behavior and proximity to a magnetic quantum critical point in BaCoAs
- 75As NQR/NMR Studies on Oxygen-deficient Iron-based Oxypnictide Superconductors LaFeAsO_{1-y} (y=0,0.25,0.4) and NdFeAsO_{0.6}
- Strong-coupling Spin-singlet Superconductivity with Multiple Full Gaps in Hole-doped BaKFeAs Probed by Fe-NMR
- Quantum Criticality in Electron-doped BaFe_{2-x}Ni_xAs_2
- 75As NMR Study of Hole-Doped Superconductor Ba1-xKxFe2As2 (Tc = 38K)
- 77Se NMR Investigation of the K(x)Fe(2-y)Se(2) High Tc Superconductor (Tc=33K)
- Antiferromagnetic Spin Fluctuation above the Superconducting Dome and the Full-Gaps Superconducting State in LaFeAsO1-xFx Revealed by 75As-Nuclear Quadrupole Resonance
- Magnetic fluctuations and superconducting properties of CaKFe4As4 studied by 75As NMR
- Potential antiferromagnetic fluctuations in hole-doped iron-pnictide superconductor Ba_{1-x}K_{x}Fe_{2}As_{2} studied by ^{75}As nuclear magnetic
- Model of the Electronic Structure of Electron-Doped Iron-Based Superconductors: Evidence for Enhanced Spin Fluctuations by Diagonal Electron Hopping
- New Superconductivity Dome in LaFeAsOF Accompanied by Structural Transition
- Doping dependence of Normal-state Property in the Iron-based Oxypnictide Superconductors LaFeAsO1-y probed by 57Fe-NMR and 75As-NMR/NQR
- Possible Superconducting Symmetry and Magnetic Correlations in K0.8Fe2Se2: A 77Se-NMR Study
- Ab initio Studies of Magnetism in the Iron Chalcogenides FeTe and FeSe
- Unconventional multiband superconductivity with nodes in single-crystalline SrFe2(As_0.65P_0.35)2 as seen via 31P-NMR and specific heat
- Superconductivity in Uncollapsed Tetragonal LaFe2As2
- Magnetic and structural transitions in LaNaFeAs single crystals
- Emergent Phases of Nodeless and Nodal Superconductivity Separated by Antiferromagnetic Order in Iron-based Superconductor (Ca4Al2O6)Fe2(As1-xPx)2: 75As- and 31P-NMR Studies
- Superconductivity and normal state properties of single-crystalline Tl0.47Rb0.34Fe1.63Se2 as seen via 77Se and 87Rb NMR
- NMR evidence for an intimate relationship between antiferromagnetic spin fluctuations and extended s-wave superconductivity in mono-crystalline SrFe2(As_{1-x}P_{x})2
- High-Tc Nodeless s_\pm-wave Superconductivity in (Y,La)FeAsO_{1-y} with Tc=50 K: 75As-NMR Study
- Phase Separation, Competition, and Volume Fraction Control in NaFeCoAs
- Antiferromagnetic Order and Superconductivity in Sr4(Mg0.5-xTi0.5+x)2O6Fe2As2 with Electron Doping: 75As-NMR Study