Visualizing the Atomic-Scale Origin of Charge–Magnetic Coupling in 2D ferromagnetic Kondo lattice Fe₅GeTe₂

Hung-Chang Hsu^1*, Parry Pei-Rui Luo¹, Ya-Ping Chiu¹

¹Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Hung-Chang Hsu, email:hsiuta617@gmail.com

The two-dimensional ferromagnet Fe₅GeTe₂ provides a model platform to study correlated orders. Here, we directly visualize at the atomic scale the spatial coherence among charge density waves (CDW), ferromagnetism (FM), and Kondo resonances. The observed CDW modulation is consistent with a band hybridization scenario influenced by Kondo interactions, while the Kondo effect further tunes the exchange interactions between Fe atoms to relieve spin frustration. Scanning tunneling microscopy and spectroscopy reveal this cooperative mechanism, showing how structural and electronic degrees of freedom act together to stabilize charge–magnetic coupling. These findings highlight Fe₅GeTe₂ as a promising system for programmable correlated states in two-dimensional magnets.

Keywords: Kondo effect, 2D ferromagnetic, scanning tunneling microscopy