Superconductivity and electronic fluctuations in Ba1-xKxFe2As2 studied by Raman scattering

Article

关键词: NEUTRON-SCATTERING;    MAGNETIC EXCITATIONS;    BA0.6K0.4FE2AS2;    SYMMETRY;    STATE;    ORDER;    GAPS;   

DOI  :  10.1103/PhysRevB.95.085125

来源: SCIE

【 摘 要 】

Using polarization-resolved electronicRaman scattering we study underdoped, optimally doped, and overdoped Ba1-xKxFe2As2 samples in the normal and superconducting states. We show that low-energy nematic fluctuations are universal for all studied doping ranges. In the superconducting state, we observe two distinct superconducting pair-breaking peaks corresponding to one large and one small superconducting gap. In addition, we detect a collective mode below the superconducting transition in the B-2g channel and determine the evolution of its binding energy with doping. Possible scenarios are proposed to explain the origin of the in-gap collective mode. In the superconducting state of the underdoped regime, we detect a reentrance transition below which the spectral background changes and the collective mode vanishes.

【 授权许可】

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