Low field63Cu NMR study of indirect nuclear spin-spin coupling in YBa2Cu3O6.9. A new approach to probe strong correlation effects in high-Tc superconductors

The authors carried out a low field (6.3 kOe) NMR measurement of the Gaussian component of63Cu nuclear spin-spin relaxation rate 1/T2G at the planar Cu site in a high-Tc superconductor YBa2Cu3O6.9 (Tc=92 K). They demonstrate that the results provide quantitative information concerning the static spin susceptibility χ′(q) at non-zero wave vector q. The detailed analysis of the data assuming a model susceptibility peaked at the corner of first …