The observation of a single gap in the superconductor SmFeAsO0.85F0.15 is reported. The gap value, its decrease with temperature and vanishing at Tc are all consistent with the Bardeen–Cooper–Schrieffer predictions, but dramatically different from that of the pseudogap behaviour in the copper oxide superconductors. The results are not compatible with models involving antiferromagnetic fluctuations, strong correlations, t-J model, and the like, originally designed for the high-Tc copper oxides.
- T. Y. Chen
- Z. Tesanovic
- C. L. Chien
