Unscreening Effect on Fe-Pnictide Superconductor

Abstract

We study a microscopic mechanism of Fe-pnictide superconductor, considering the screening effects of Coulomb interaction in addition to the conventional spin-fluctuation mechanism. It is shown that, by electron doping, the transition temperature of superconductivity increases due to the "unscreening" effect even though the density of states decrease, while that of spin-density wave rapidly decreases due to breaking of nesting conditions. Our results give a clear interpretation to the mystery of interrelation between T_c and the density of states observed in the Fe-pnictide superconductors.

4 pages, 5 figures

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Cited by in corpus (8)

• Pnictogen height as a possible switch between high-T_c nodeless and low-T_c nodal pairings in the iron based superconductors
• Impurity-induced in-gap state and Tc in sign-reversing s-wave superconductors: analysis of iron oxypnictide superconductors
• Single Impurity Problem in Iron-Pnictide Superconductors
• Odd parity pairing and nodeless anti-phase $s^{\pm }$ in Iron-Based Superconductors
• Normal State Spin Dynamics of Five-band Model for Iron-pnictides
• Orbital-Selective Superconductivity and the Effect of Lattice Distortion in Iron-Based Superconductors
• Simple Real-Space Picture of Nodeless and Nodal s-wave Gap Functions in Iron Pnictide Superconductors
• Contrast of LiFeAs with isostructural, isoelectronic, and non-superconducting MgFeGe