Abrupt change in the energy gap of superconducting Ba 1-xK xFe 2As 2 single crystals with hole doping

W. Malaeb, T. Shimojima, Y. Ishida, K. Okazaki, Y. Ota, K. Ohgushi, K. Kihou, T. Saito, C. H. Lee, S. Ishida, M. Nakajima, S. Uchida, H. Fukazawa, Y. Kohori, A. Iyo, H. Eisaki, C. T. Chen, S. Watanabe, H. Ikeda, S. Shin

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51 Citations (Scopus)


We performed a laser angle-resolved photoemission spectroscopy (ARPES) study on a wide doping range of Ba 1-xK xFe 2As 2 (BaK) and precisely determined the doping evolution of the superconducting gaps in this compound. The gap size of the outer hole Fermi-surface (FS) sheet around the Brillouin zone (BZ) center shows an abrupt drop with overdoping (for x 0.6) while the inner and middle FS gaps roughly scale with T c. This is accompanied by the simultaneous disappearance of the electron FS sheet with similar orbital character at the BZ corner. These results indicate the different contributions of X2-Y2 and XZ/YZ orbitals to superconductivity in BaK and can hardly be completely reproduced by the available theories on iron-based superconductors.

Original languageEnglish
Article number165117
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number16
Publication statusPublished - 2012 Oct 10
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics


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