Spin Fluctuations, Interband Coupling, and Unconventional Pairing in Iron-based Superconductors

Abstract

Based on an effective two-band model and using the fluctuation-exchange (FLEX) approach, we explore spin fluctuations and unconventional superconducting pairing in Fe-based layer superconductors. It is elaborated that one type of interband antiferromagnetic (AF) spin fluctuation stems from the interband Coulomb repulsion, while the other type of intraband AF spin fluctuation originates from the intraband Coulomb repulsion. Due to the Fermi-surface topology, a spin-singlet extended s-wave superconducting state is more favorable than the nodal $d_{XY}$-wave state if the interband AF spin fluctuation is more significant than the intraband one, otherwise vice versa. It is also revealed that the effective interband coupling plays an important role in the intraband pairings, which is a distinct feature of the present two-band system.

4 pages, 4 figures, to appear in New Journal of Physics focus issue on iron-based superconductors

References in corpus (24)

• Unconventional sign-reversing superconductivity in LaFeAsO_(1-x)F_x
• Magnetic Order versus superconductivity in the Iron-based layered La(O1-xFx)FeAs systems
• Superconductivity at 43 K in Samarium-arsenide Oxides $SmFeAs{O}_{1-x}{F}_x$
• Unconventional pairing originating from disconnected Fermi surfaces in superconducting LaFeAsO${}_{1-x}$F${}_x$}
• LaFeAsO${}_{1-x}$F${}_x$: A low carrier density superconductor near itinerant magnetism
• Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO${}_{1-x}$F${}_x$FeAs
• Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2
• Competing Orders and Spin-Density-Wave Instability in La(O${}_{1-x}$F${}_x$)FeAs
• Is LaO${}_{1-x}$F${}_x$FeAs an electron-phonon superconductor ?
• Superconductivity at 25 K in hole doped $(L{a}_{1-x}S{r}_x)OFeAs$
• A minimal two-band model for the superconducting Fe-pnictides
• Superconductivity at 52 K in iron-based F-doped layered quaternary compound Pr[O1-xFx]FeAs
• Electron-Hole Symmetry and Magnetic Coupling in Antiferromagnetic LaOFeAs
• Theory of magnetic excitations in iron-based layered superconductors
• Proximity of antiferromagnetism and superconductivity in LaO${}_{1-x}$F${}_x$FeAs: effective Hamiltonian from ab initio studies
• Antiferromagnetic superexchange interactions in LaOFeAs
• Doping-dependent Phase Diagram of LaO{\it M}As ({\it M}=V--Cu) and Electron-type Superconductivity near Ferromagnetic Instability
• Spin-triplet p-wave pairing in a 3-orbital model for iron pnictide superconductors
• Strong-coupling theory of superconductivity in a degenerate Hubbard model
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Point-Contact Spectroscopy of Iron-Based Layered Superconductor LaO${}_{0.9}$F${}_{0.1-\delta }$FeAs
• A Generic Two-band Model for Unconventional Superconductivity and Spin-Density-Wave Order in Electron and Hole Doped Iron-Based Superconductors
• Determining gap nodal structures in Fe-based superconductors: angle-dependence of the low temperature specific heat in an applied magnetic field
• Band structure renormalization and weak pseudogap behavior in Na_{0.33}CoO_2: Fluctuation exchange study based on a single band model

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