Theory for Inelastic Neutron Scattering in Orthorhombic High-Tc Superconductors

TL;DR

This paper develops a Fermi-liquid-based theoretical model to analyze the in-plane anisotropy of spin susceptibility in orthorhombic high-Tc cuprates, aligning well with experimental neutron scattering data and predicting anisotropic resonance peak dispersion.

Contribution

It introduces a generalized RPA-type theory incorporating anisotropic hopping and mixed symmetry of the superconducting gap for orthorhombic cuprates, advancing understanding of their spin dynamics.

Findings

Good agreement with neutron scattering data on YBa2Cu3O7-δ

Prediction of strongly anisotropic in-plane resonance dispersion

Demonstration of anisotropic spin susceptibility in orthorhombic superconductors

Abstract

Using a Fermi-liquid-based theory we calculate the in-plane anisotropy of the spin susceptibility for hole-doped high-T_c cuprates. Employing the two-dimensional one-band Hubbard model and a generalized RPA-type theory we consider anisotropic hopping matrix elements ($t_x \neq t_y$) 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 YBa{2}Cu{3}O{7-\delta} and find good agreement. Furthermore, we predict a strongly anisotropic in-plane dispersion of the resonance peak.