# ARPES signature of the competition between magnetic order and Kondo effect in CeCoGe3

## TL;DR

This study uses high-resolution photoemission to observe how magnetic order and Kondo effect compete in CeCoGe3, revealing their manifestation in quasiparticle bands and their temperature-dependent interplay.

## Contribution

First direct spectroscopic evidence of the competition between magnetic order and Kondo effect in a heavy fermion system with local-moment antiferromagnetism.

## Key findings

- Weakly dispersive 4f band at the Fermi level observed
- Kondo effect shows a logarithmic temperature dependence
- Competition between magnetic order and Kondo effect identified

## Abstract

The competition between magnetic order and Kondo effect is essential for the rich physics of heavy fermion systems. Nevertheless, how such competition is manifested in the quasiparticle bands in a real periodic lattice remains elusive in spectroscopic experiments. Here we report a high-resolution photoemission study of the antiferromagnetic Kondo lattice system CeCoGe3 with a high TN1 of 21K. Our measurements reveal a weakly dispersive 4f band at the Fermi level near the Z point, arisingfrom moderate Kondo effect. The intensity of this heavy 4f band exhibits a logarithmic increase with lowering temperature and begins to deviate from this Kondo-like behavior below 25 K, just above TN1, and eventually ceases to grow below 12 K. Our work provides direct spectroscopic evidence for the competition between magnetic order and the Kondo effect in a Kondo lattice system with local-moment antiferromagnetism, indicating a distinct scenario for the microscopic coexistence and competition of these phenomena, which might be related to the real-space modulation.