Spin correlation in high-T-c cuprate HgBa2Ca2Cu3O8+delta with T-c=133 K - An origin of T-c-enhancement evidenced by Cu-63-NMR study

The Knight shift, the nuclear spin-lattice relaxation rate, 1/T-1, and the transverse relaxation rate, 1/T-20, of (CU)-C-63 have been separately measured for the square and the pyramidal CuO2 planes in HgBa2Ca2Cu3O8+delta (Hg1223) with the highest transition temperature, T-c = 133 K to date. From the quantitative analysis of 1/T-1 and 1/T-2G, it is shown that the product of the staggered susceptibility and the characteristic energy of spin fluctuations around a zone boundary, chi(Q) Gamma(Q) for the square CuO2 plane site is larger than that for YBa2Cu3O7 (YBCO7), although that for the pyramidal CuO2 plane site is almost the same. This enhancement of chi(Q) Gamma(Q) for the square site is considered to be responsible for the higher T-c in Hg1223 than in YBCO7.