TY - JOUR
T1 - Universality of superconducting gaps in overdoped Ba0.3K 0.7Fe2As2 observed by angle-resolved photoemission spectroscopy
AU - Nakayama, K.
AU - Sato, T.
AU - Richard, P.
AU - Xu, Y. M.
AU - Kawahara, T.
AU - Umezawa, K.
AU - Qian, T.
AU - Neupane, M.
AU - Chen, G. F.
AU - Ding, H.
AU - Takahashi, T.
PY - 2011/1/10
Y1 - 2011/1/10
N2 - We have performed angle-resolved photoemission spectroscopy on the overdoped Ba0.3K0.7Fe2As2 superconductor (Tc=22 K). We demonstrate that the superconducting (SC) gap on each Fermi surface (FS) is nearly isotropic whereas the gap value varies from 4.4 to 7.9 meV on different FSs. By comparing with under- and optimally doped Ba1-xKxFe2As2, we find that the gap value on each FS nearly scales with Tc over a wide doping range (0.25≤x≤0.7). Although the FS volume and the SC gap magnitude are strongly doping dependent, the multiple nodeless gaps can be commonly fitted by a single gap function assuming pairing up to the second nearest neighbor, suggesting the universality of the short-range pairing states with the s±-wave symmetry.
AB - We have performed angle-resolved photoemission spectroscopy on the overdoped Ba0.3K0.7Fe2As2 superconductor (Tc=22 K). We demonstrate that the superconducting (SC) gap on each Fermi surface (FS) is nearly isotropic whereas the gap value varies from 4.4 to 7.9 meV on different FSs. By comparing with under- and optimally doped Ba1-xKxFe2As2, we find that the gap value on each FS nearly scales with Tc over a wide doping range (0.25≤x≤0.7). Although the FS volume and the SC gap magnitude are strongly doping dependent, the multiple nodeless gaps can be commonly fitted by a single gap function assuming pairing up to the second nearest neighbor, suggesting the universality of the short-range pairing states with the s±-wave symmetry.
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U2 - 10.1103/PhysRevB.83.020501
DO - 10.1103/PhysRevB.83.020501
M3 - Article
AN - SCOPUS:79551623041
VL - 83
JO - Physical Review B - Condensed Matter and Materials Physics
JF - Physical Review B - Condensed Matter and Materials Physics
SN - 0163-1829
IS - 2
M1 - 020501
ER -