title: Model of the electronic structure of electron-doped iron-based superconductors: evidence for enhanced spin fluctuations by diagonal electron hopping.
abstract: We present a theoretical understanding of the superconducting phase diagram of the electron-doped iron pnictides. We show that, besides the Fermi surface nesting, a peculiar motion of electrons, where the next nearest neighbor (diagonal) hoppings between iron sites dominate over the nearest neighbor ones, plays an important role in the enhancement of the spin fluctuation and thus superconductivity. In the highest T(c) materials, the crossover between the Fermi surface nesting and this "prioritized diagonal motion" regime occurs smoothly with doping, while in relatively low T(c) materials, the two regimes are separated and therefore results in a double dome T(c) phase diagram.
authors: Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors: Katsuhiro
authors: K
authors: Suzuki
authors: Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors: Hidetomo
authors: H
authors: Usui
authors: Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
authors: Soshi
authors: S
authors: Iimura
authors: Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
authors: Yoshiyasu
authors: Y
authors: Sato
authors: Materials Research Center for Element Strategy, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
authors: Satoru
authors: S
authors: Matsuishi
authors: Materials and Structures Laboratory, Tokyo Institute of Technology, Yokohama 226-8503, Japan and Frontier Research Center, Tokyo Institute of Technology, Yokohama 226-8503, Japan.
authors: Hideo
authors: H
authors: Hosono
authors: Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan.
authors: Kazuhiko
authors: K
authors: Kuroki