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

Abstract

Temperature ( T ) dependence of the static and the dynamic electron spin-spin correlation is discussed through the planar 63 Cu(2) nuclear spin-spin relaxation rate 1/ 63 T G and the spin-lattice relaxation rate 1/ 63 T 1 T for YBa 2 Cu 3 O 6.6 ( T c ∼60 K), YBa 2 Cu 4 O 8 ( T c ∼82 K), YBa 2 Cu 3 O 6.98 ( T c ∼92 K), and Tl 2 Ba 2 CuO 6+δ ( T c ∼85 K). The restricted moment sums S =( 63 T 1 T ) AF /( 63 T 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 c < T <300 K). The T -independent S indicates the validity of (1/ 63 T 1 ) AF ∝ T χ( Q ) for the antiferromagnetic Fermi liquid model. From the experimental values of S , we estimate the ratio 2α s T A / T 0 of the characteristic spin-fluctuation parameters 2α s T A and T 0 .