Magnetic and superconducting instabilities in a hybrid model of itinerant/localized electrons for iron pnictides

Article

关键词: PHASE-DIAGRAM;    ITINERANT;    ORDER;    FEAS;   

DOI  :  10.1103/PhysRevB.84.054527

来源: SCIE

【 摘 要 】

We study a unified mechanism for spin-density-wave (SDW) and superconductivity in a minimal model in which itinerant electrons and local moments coexist as previously proposed for the iron pnictides [Kou, Li, Weng, EPL 88, 17010 (2009)]. The phase diagram obtained at the mean-field level is in qualitative agreement with the experiment, which shows how the magnetic and superconducting (SC) instabilities are driven by the critical coupling between the itinerant/localized electrons. The spin and charge response functions at the random-phase-approximation level further characterize the dynamical evolution of the system. In particular, the dynamic spin susceptibility displays a Goldstone mode in the SDW phase, which evolves into a gapped resonance-like mode in the SC phase. The latter persists all the way into the normal state above T(c) where a strong scattering between the itinerant electrons and local moments is restored, as an essential feature of the model.

【 授权许可】

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