Magnetic Excitations in the Site-Centered Stripe Phase: Spin Wave Theory of Coupled Three-Leg Ladders

TL;DR

This paper presents a detailed spin wave theory analysis of coupled three-leg ladders to model magnetic excitations in site-centered stripe phases, aligning well with experimental data and clarifying the nature of magnetic order.

Contribution

It offers a comprehensive spin wave theory analysis of coupled three-leg ladders, demonstrating their effectiveness in describing magnetic excitations in site-centered stripe phases.

Findings

Only the site-centered models exhibit magnetic order.

The spin wave theory of coupled three-leg ladders aligns with experimental data.

The analysis clarifies the magnetic structure in stripe-ordered cuprates.

Abstract

The success of models of coupled two-leg spin ladders in describing the magnetic excitation spectrum of La_{2-x}Ba_xCuO_4 had been interpreted previously as evidence for bond-centered stripes. In a recent article, however, we have determined the magnetic coupling induced by the charge stripes between bond- or site-centered spin stripes modeled by two- or three-leg ladders, respectively. We found that only the site-centered models order. We further indicated excellent agreement of a fully consistent analysis of coupled three-leg ladders using a spin wave theory of bond with the experimental data. Here, we provide a full and detailed account of this analysis.