Orbital origin of magnetic moment enhancement induced by charge density wave in kagome FeGe

TL;DR

This study uncovers how orbital hybridization influences magnetic moment enhancement during the charge density wave transition in kagome FeGe, revealing an orbital-based mechanism behind the interplay of charge order and magnetism.

Contribution

It demonstrates the orbital origin of magnetic moment enhancement in FeGe during the CDW phase transition using experimental and computational methods.

Findings

Orbital hybridization between Fe 3d and Ge 4p states increases with temperature.

Charge density wave transition affects orbital coupling and magnetic properties.

Orbital effects are crucial for understanding the interplay of charge order and magnetism.

Abstract

Interactions among various electronic states such as CDW, magnetism, and superconductivity are of high significance in strongly correlated systems. While significant progress has been made in understanding the relationship between CDW and superconductivity, the interplay between CDW and magnetic order remains largely elusive. Kagome lattices, which intertwine nontrivial topology, charge order, and magnetism, offer an ideal platform for such studies. The kagome magnet FeGe, hosting the unique coupling between CDW and magnetism, has recently garnered considerable attention in that respect. Here we reveal the significant role of the orbital coupling effect during the CDW phase transition, highlighting the orbital origin of the magnetic moment enhancement in FeGe. Our X ray absorption experiments and first principles calculations illuminate the temperature dependent behavior of Fe3d_Ge4p orbital hybridization and corroborate its pivotal impact on the magnetic properties of FeGe. These findings introduce an orbital dimension to the correlation between charge and magnetic degrees of freedom, advancing our understanding of the intriguing quantum phases resulting from this interplay.