Spin dynamics of stripes

TL;DR

This paper models the spin dynamics of stripe phases in high-temperature superconductors using spin-wave theory, revealing how stripe spacing influences resonance features and aligning well with experimental observations.

Contribution

It introduces a simple spin-only model to analyze stripe spin dynamics, capturing key experimental features and their dependence on stripe parameters.

Findings

Resonance frequency scales inversely with stripe spacing at low doping.

Calculated magnon dispersion matches experimental data.

Both acoustic and optical magnon bands are included in the analysis.

Abstract

The spin dynamics of stripes in high-temperature superconductors and related compounds is studied in the framework of a spin-wave theory for a simple spin-only model. The magnon dispersion relation and the magnetic structure factor are calculated for diagonal and vertical stripes. Acoustical as well as optical bands are included in the analysis. The incommensurability and the $\pi$ resonance appear as complementary features of the band structure at different energy scales. The dependence of spin-wave velocities and resonance frequencies on the stripe spacing and coupling is calculated. At low doping, the resonance frequency is found to scale roughly inversely proportional to the stripe spacing. The favorable comparison of the results with experimental data suggests that the spin-only model provides a suitable and simple basis for calculating and understanding the spin dynamics of stripes.