Unusual structural tuning of magnetism in cuprate perovskites

TL;DR

This study investigates how structural modifications in Se_{1-x}Te_{x}CuO_{3} alloys influence their magnetic interactions, revealing that the position of Se and Te atoms, rather than super-exchange angles, is key to tuning magnetism.

Contribution

The paper uncovers a novel mechanism where the position of dummy atoms Se and Te, not the super-exchange angles, controls magnetic interactions in cuprate perovskites.

Findings

Structural tuning linked to Se and Te atom positions.

Density functional theory and other methods used to analyze effects.

Potential for engineering magnetic properties in solids.

Abstract

Understanding the structural underpinnings of magnetism is of great fundamental and practical interest. Se_{1-x}Te_{x}CuO_{3} alloys are model systems for the study of this question, as composition-induced structural changes control their magnetic interactions. Our work reveals that this structural tuning is associated with the position of the supposedly dummy atoms Se and Te relative to the super-exchange (SE) Cu--O--Cu paths, and not with the SE angles as previously thought. We use density functional theory, tight-binding, and exact diagonalization methods to unveil the cause of this surprising effect and hint at new ways of engineering magnetic interactions in solids.