Detailed structure of the magnetic excitation spectra χ″(q, ω) of the superconducting oxide YBa 2Cu 3O 6.5 (the transition temperature T c ≅ 52K) in the wave vector (q)- and the energy(ω)-space, and its temperature (T) dependence have been studied. By adopting an effective energy dispersion of the quasi particles which can reproduce the shape of the Fermi surface and by introducing the exchange interaction between the Cu spins, a rather satisfactory agreement between the calculation and the experimentally observed data can be obtained. In the study, it has been found that the effects of the quasi particle-energy broadening on the excitation spectra χ″ (q,ω) is important. The sharp resonance peak observed at w ∼ 40 meV for the optimally doped system of YBa 2Cu 3O y can be naturally reproduced by the present model.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)