Spin waves and magnetic exchange interactions in the spin ladder compound RbFe$_2$Se$_3$

TL;DR

This study uses inelastic neutron scattering to analyze spin waves in RbFe$_2$Se$_3$, revealing universal magnetic exchange interactions similar to those in iron-based superconductor parent compounds, indicating common spin dynamics.

Contribution

It provides the first detailed characterization of spin wave dynamics in RbFe$_2$Se$_3$, highlighting the universality of magnetic exchange interactions across Fe-based materials.

Findings

Comparable $SJ$ values along leg and rung directions

Universal spin wave behavior across Fe-based compounds

Irrelevance of fermiology for stripe order

Abstract

We report an inelastic neutron scattering study of the spin waves of the one-dimensional antiferromagnetic spin ladder compound RbFe$_2$Se$_3$. The results reveal that the products, $SJ$'s, of the spin $S$ and the magnetic exchange interactions $J$'s along the antiferromagnetic (leg) direction and the ferromagnetic (rung) direction are comparable with those for the stripe ordered phase of the parent compounds of the iron-based superconductors. The universality of the $SJ$'s implies nearly universal spin wave dynamics and the irrelevance of the fermiology for the existence of the stripe antiferromagnetic order among various Fe-based materials.