2010/02/28 by Hiroaki Ikeda, Ryotaro Arita, J. Kuneš +1 · 51 citations
Materials Science · Physics and Astronomy · #Condensed matter physics #Cuprate #Doping #Electron #Excitation #Fermi level #Fermi surface #Iron-based superconductors research #Phase (matter) #Phase diagram #Physics #Physics of Superconductivity and Magnetism #Pseudogap #Quantum mechanics #Rare-earth and actinide compounds #Spin (aerodynamics) #Superconductivity #cond-mat.str-el #cond-mat.supr-con
paper · pdf · open access · doi:10.1103/physrevb.82.024508
published in Physical Review B 82(2) (American Physical Society) · 4 pages, 5 figures
openalex publication_date 2010/07/14 · arxiv created 2010/07/20 · arxiv updated 2010/07/21 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
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 \mathbitQ=(\ensuremathπ,0), which becomes critical at low temperature. The low-energy spin excitations in the heavily hole-doped region are characterized by weak \mathbitQ dependence. The electron doping leads to an appearance of a pseudogap in spin-excitation spectrum. Correspondingly, the NMR-1/T1 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.