Magnetic Excitations in Bilayer High-Temperature Superconductors with Stripe Correlations

TL;DR

This paper models magnetic excitations in bilayer high-temperature superconductors with stripe correlations using coupled spin ladders, successfully explaining neutron scattering data and predicting behaviors for different stripe configurations.

Contribution

It introduces a coupled spin ladder model for bilayer superconductors with stripe correlations, providing a quantitative explanation of neutron scattering results and making new predictions for bilayer systems.

Findings

Neutron resonance peak explained by a saddle point in magnetic excitation dispersion.

Quantitative match with neutron scattering data for single-layer cuprates.

Predictions for magnetic excitations in bilayer systems with different stripe phases.

Abstract

The universal behaviour of the magnetic excitations in high-temperature superconductors is described in a model with static stripes retaining only the localized spin degrees of freedom. The stripes are represented by a model of coupled two-leg spin ladders. We start from the results obtained previously by continuous unitary transformations for an isolated spin ladder. A quantitative description of neutron scattering data is reached, using a model for a single cuprate layer with well established values of the exchange coupling constants. The neutron resonance peak is explained in terms of a saddle point in the dispersion of the magnetic excitations. Here we make predictions for bilayer systems with in-phase or out-of-phase stripe correlations. The results may serve as a guide for future experimental analyses.