Theory for inelastic neutron scattering in orthorhombic high- Tc superconductors

Abstract

Using a Fermi-liquid-based theory we calculate the in-plane anisotropy of the spin susceptibility χ (q,ω) for hole-doped high- Tc cuprates. Employing the two-dimensional one-band Hubbard model and a generalized RPA-type theory we consider anisotropic hopping matrix elements (tx ≠ ty) and a mixing of d - and s -wave symmetry of the superconducting order parameter in order to describe orthorhombic superconductors. We compare our calculations with available inelastic neutron scattering data on untwinned Y Ba2 Cu3 O6+x and find good agreement. Furthermore, we predict a strongly anisotropic in-plane dispersion of the resonance peak. © 2006 The American Physical Society.