FRUSTRATED SPIN (J-J') SYSTEMS DO NOT MODEL THE MAGNETIC-PROPERTIES OF HIGH-TEMPERATURE SUPERCONDUCTORS

We study the t - J model with one hole and the frustrated Heisenberg J - J' model in a square lattice. Specifically, we compute and compare for both, the doped and frustrated models, the dynamic spin-spin structure factor S(q, omega), and the B1g Raman scattering spectrum R(omega) at zero temperature. The behavior of these quantities differs between the t - J and the J - J' models. We observe that both the B1g Raman spectrum as well as the structure factor for the t - J model are in qualitative agreement with experimental measurements while the corresponding results for the J - J' model are not. These results indicate that the magnetic behavior of doped systems cannot be accurately modeled by a purely spin Hamiltonian. These results are of relevance to the claim that the effect of adding holes (doping) on the magnetic properties of the quantum Heisenberg antiferromagnet can be described by introducing second and sometimes third nearest-neighbor couplings, J' and J" respectively, in the original (undoped) Hamiltonian.