Intertwining of Magnetism and Charge Ordering in Kagome FeGe

Recent experiments report a chargedensity wave (CDW)in the antiferromagnetFeGe, but the nature of the charge ordering and the associated structuraldistortion remains elusive. We discuss the structural and electronicproperties of FeGe. Our proposed ground state phase accurately capturesatomic topographies acquired by scanning tunneling microscopy. Weshow that the 2 x 2 x 1 CDW likely results from the Fermisurface nesting of hexagonal-prism-shaped kagome states. FeGe is foundto exhibit distortions in the positions of the Ge atoms instead ofthe Fe atoms in the kagome layers. Using in-depth first-principlescalculations and analytical modeling, we demonstrate that this unconventionaldistortion is driven by the intertwining of magnetic exchange couplingand CDW interactions in this kagome material. The movement of Ge atomsfrom their pristine positions also enhances the magnetic moment ofthe Fe kagome layers. Our study indicates that magnetic kagome latticesprovide a material candidate for exploring the effects of strong electroniccorrelations on the ground state and their implications for transport,magnetic, and optical responses in materials.