Scaling Relation of Electron Spin-Spin Correlation in High-Temperature Superconductors

抄録

Temperature (T) dependence of the static and the dynamic electron spin-spin correlation is discussed through the planar ⁶³Cu(2) nuclear spin-spin relaxation rate 1/⁶³T_G and the spin-lattice relaxation rate 1/⁶³T₁T for YBa₂Cu₃O_6.6 (T_c-- 60, K), YBa₂Cu₄O₈ (T_c-- 82, K), YBa₂Cu₃O_6.98 (T_c-- 92, K), and Tl₂Ba₂CuO_6+δ (T_c-- 85, K). The restricted moment sums S=(⁶³T₁T)_AF/(⁶³T_G)² [-- χ (Q)Γ(Q)] for the lightly doped Cu oxides tend to have constant values at high temperatures and those for the other ones are nearly T-independent at all the measured T (T_c63T₁)_AF∝ Tχ (Q) for the antiferromagnetic Fermi liquid model. From the experimental values of S, we estimate the ratio 2α _sT_A/T₀ of the characteristic spin-fluctuation parameters 2α _sT_A and T₀.