Evidence for site-centered stripes from magnetic excitations in CuO superconductors

TL;DR

This paper provides evidence that magnetic excitations in CuO superconductors support the presence of site-centered stripe order, with theoretical models aligning well with experimental data.

Contribution

It demonstrates that only site-centered stripe models predict magnetic order and shows that a three-leg ladder model accurately describes experimental magnetic excitations.

Findings

Site-centered stripe models predict magnetic order.

Three-leg ladder models match experimental magnetic spectra.

Bond-centered models do not order.

Abstract

The success of models of coupled two-leg spin ladders in describing the magnetic excitation spectrum of La_[2-x]Ba_xCuO_4 has been widely interpreted as evidence for bond-centered stripes. Here, we determine the magnetic coupling induced by the charge stripes between bond- or site-centered spin stripes modeled by two- or three-leg ladders, respectively. We find that only the site-centered models order. We further report excellent agreement of a fully consistent analysis of coupled three-leg ladders using a spin wave theory of bond operators with the experiment.