Staggered Spin Susceptibility in YBa₂Cu₃O_6.98andYBa₂Cu₄O₈Observed by Cu Nuclear Spin-Spin Relaxation

Abstract

The temperature ( T ) dependence of the static staggered spin susceptibility χ( Q ) for the high T c Cu oxides, YBa 2 Cu 3 O 6.98 and YBa 2 Cu 4 O 8 , extracted from the Cu nuclear spin-spin relaxation measurements is discussed. The self-consistent-renormalization (SCR) calculation for a two dimensional antiferromagnetic Fermi liquid well reporoduces the experimental Curie-Weiss-type T -dependence of χ( Q ), but the random-phase-approximation does not. This shows that the Curie-Weiss-type χ( Q ) of the high T c Cu oxides results from the SCR spin fluctuations at finite temperatures but not from the strong nesting of the Fermi surface.