Doping dependence of spin fluctuations and electron correlations in iron pnictides

Article

关键词: SUPERCONDUCTIVITY;    BA0.6K0.4FE2AS2;    RE;   

DOI  :  10.1103/PhysRevB.82.024508

来源: SCIE

【 摘 要 】

Doping dependence of the spin fluctuations and the electron correlations in the effective five-band Hubbard model for iron pnictides is investigated using the fluctuation-exchange approximation. For a moderate hole doping, we find a dominant low-energy spin excitation at Q=(pi,0), which becomes critical at low temperature. The low-energy spin excitations in the heavily hole-doped region are characterized by weak Q dependence. The electron doping leads to an appearance of a pseudogap in spin-excitation spectrum. Correspondingly, the NMR-1/T(1) relaxation rate is strongly enhanced on the hole-doped side and suppressed on the electron-doped side of the phase diagram. This behavior can be to large extent understood by systematic changes of the Fermi-surface topology.

【 授权许可】

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