Unconventional superconducting characteristics in the multilayered high-T-c cuprate (Cu0.6C0.4)Ba2Ca3Cu4O12+y probed by Cu-63 NMR

We report Cu-63-NMR studies of the multilayered high-T-c cuprate (Cu0.6C0.4 )Ba2Ca3Cu4O12+y(Cu1234) with T-c = 117 K. In the normal state, the Knight s hift give evidence that the inner CuO2 planes (IP) are underdoped, whereas the outer ones (OP) are heavily overdoped. In the superconducting (SC) stat e, it is shown that the SC gap fully develops below T-c =117 K in the IP, w hereas that in the OP develops moderately below T-c = 117 K, but markedly b elow T-c2 = 60 K. We propose that these dissimilarities are caused by the l arge difference of doping levels between the IP and the OP, and that the bu lk SC transition at T-c = 117 K is triggered by the IP in Cu1234.