Spin correlations among the charge carriers in an ordered stripe phase

TL;DR

This study investigates the magnetic excitation spectrum in stripe-ordered La5/3Sr1/3NiO4, revealing diffuse, dispersive spin correlations linked to dynamic antiferromagnetic interactions among stripe electrons.

Contribution

It provides new insights into the low-energy magnetic excitations and dynamic correlations in stripe-ordered nickelates using neutron scattering.

Findings

Diffuse magnetic scattering forms a square pattern aligned with stripe directions.

The scattering is dispersive with a maximum energy of ~10 meV.

The signal diminishes with temperature, nearly disappearing at 100 K.

Abstract

We have observed a diffuse component to the low-energy magnetic excitation spectrum of stripe-ordered La5/3Sr1/3NiO4 probed by neutron inelastic scattering. The diffuse scattering forms a square pattern with sides parallel and perpendicular to the stripe directions. The signal is dispersive, with a maximum energy of ~10 meV. Probed at 2 meV the scattering decreases in strength with increasing temperature, and is barely visible at 100 K. We argue that the signal originates from dynamic, quasi- one-dimensional, antiferromagnetic correlations among the stripe electrons.