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】
Free