q-dependent neutron-scattering measurements of the dynamic susceptibility χ"(q,ω) in superconducting YBa2Cu3O6.6 are presented. The observed magnetic scattering near the antiferromagnetic zone center has a nontrivial, approximately flat-topped q dependence. A separable model of the susceptibility, χ"(q,ω)=χ"(ω)F(q), is found to describe this scattering at all energies in the range 2 meV ≤Latin small letter h with strokeω≤40 meV. Measurements at temperatures above and below Tc=46 K indicate that the q-dependent "shape" function, F(q), is the same in both the superconducting and normal states. A phenomenological expression for F(q) is presented and the physical significance of its parametrization is discussed. These results are compared with current theories in the literature.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics