Author/Authors :
Ou، نويسنده , , H.W. and ZHANG، نويسنده , , Y. and Zhao، نويسنده , , J.F. and Wei، نويسنده , , J. and Shen، نويسنده , , D.W. and Zhou، نويسنده , , B. and Yang، نويسنده , , L.X. and Chen، نويسنده , , F. and Xu، نويسنده , , M. and He، نويسنده , , C. and Liu، نويسنده , , R.H. and Arita، نويسنده , , M. and Shimada، نويسنده , , K. and Namatame، نويسنده , , H. and Taniguchi، نويسنده , , M. and Chen، نويسنده , , Y. and Chen، نويسنده , , X.H. and Feng، نويسنده , , D.L.، نويسنده ,
Abstract :
We investigated the temperature dependence of the density-of-states in the iron-based superconductor SmO1−xFxFeAs (x=0,0.12,0.15,0.2) with high resolution angle-integrated photoemission spectroscopy. The density-of-states suppression is observed with decreasing temperature in all samples, revealing two characteristic energy scales (10 meV and 80 meV). However, no obvious doping dependence is observed. We argue that the 10 meV suppression is due to an anomalously doping-independent normal state pseudogap, which becomes the superconducting gap once in the superconducting state; and alert the possibility that the 80 meV-scale suppression might be an artifact of the polycrystalline samples.
Keywords :
E. Angle-integrated photoemission spectroscopy , D. Superconducting gap and pseudogap , A. Iron-based superconductor