Multiple scattering camouflaged as magnetic stripes in single crystals of superconducting (La,Sr)$_2$CuO$_4$

TL;DR

This study reveals that apparent magnetic stripe signals in neutron diffraction experiments on (La,Sr)$_2$CuO$_4$ are actually due to multiple scattering and crystal twinning, not intrinsic magnetic order, highlighting the importance of careful analysis.

Contribution

The paper demonstrates that spurious magnetic signals in neutron diffraction can arise from multiple scattering and twinning, providing a method to distinguish genuine magnetic signals from artifacts.

Findings

Spurious signals depend on neutron energy, peaking at 4.6 meV.

Calculated scattering intensity including multiple scattering and twinning matches experimental data.

Highlights the necessity of analysis to avoid misinterpreting scattering artifacts as magnetic order.

Abstract

Neutron diffraction has been a very prominent tool to investigate high-temperature superconductors, in particular through the discovery of an incommensurate magnetic signal known as stripes. We here report the findings of a neutron diffraction experiment on the superconductor (La,Sr)$_2$CuO$_4$, where a spurious signal appeared to be magnetic stripes. The signal strength was found to be strongly dependent on the neutron energy, peaking at $E = 4.6$~meV. We therefore attribute the origin of this signal to be a combination of multiple scattering and crystal twinning. A forward calculation of the scattering intensity including these two effects almost completely recovers our experimental observations. We emphasise the need for employing such analysis when searching for ways to avoid spurious scattering signals.