2001/07/06 by Jan Brinckmann, Patrick A. Lee · 2 citations
Chemistry · Physics and Astronomy · #Advanced Condensed Matter Physics #Advanced NMR Techniques and Applications #Physics of Superconductivity and Magnetism #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.65.014502
published as Phys. Rev. B 65 (1), 014502 (2002) · 17pp including 14 figures
arxiv created 2001/07/06 · openalex publication_date 2001/11/29 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The magnetic excitation spectrum of the t\ensuremath-t^\ensuremath'\ensuremath-J model is studied in mean-field theory and compared to inelastic neutron-scattering (INS) experiments on YBa2Cu3O6+y (YBCO) and Bi2Sr2CaCu2O_8+\ensuremathδ (BSCCO) superconductors. Within the slave-particle formulation the dynamical spin response is calculated from a renormalized Fermi liquid with an effective interaction \ensuremath∼J in the magnetic particle-hole channel. We obtain the so-called ``41-meV resonance'' at wave vector (\ensuremathπ,\ensuremathπ) as a collective spin-1 excitation in the d-wave superconducting state. It appears sharp (undamped), if the underlying Fermi surface is holelike with a sufficient next-nearest-neighbor hopping t^\ensuremath'<0. The double-layer structure of YBCO or BSCCO is not important for the resonance to form. The resonance energy \ensuremathωres and spectral weight at optimal doping come out comparable to experiment. The observed qualitative behavior of \ensuremathωres with hole filling is reproduced in the underdoped as well as overdoped regime. A second, much broader peak becomes visible in the magnetic excitation spectrum if the 2D wave vector is integrated over. It is caused by excitations across the maximum gap, and in contrast to the resonance its energy is almost independent of doping. At energies above or below \ensuremathωres the commensurate resonance splits into incommensurate peaks, located off (\ensuremathπ,\ensuremathπ). Below \ensuremathωres the intensity pattern is of ``parallel'' type and the dispersion relation of incommensurate peaks has a negative curvature. This is in accordance with recent INS experiments on YBCO.