Direct observation of heavy quasiparticles in the Kondo lattice CeIn3

TL;DR

This study provides direct experimental evidence of weakly dispersive heavy quasiparticles in CeIn3, revealing weak hybridization between f electrons and conduction electrons, crucial for understanding heavy-fermion behavior.

Contribution

First direct observation of weakly dispersive quasiparticle bands and hybridization gap in CeIn3 using advanced spectroscopic techniques.

Findings

Weak quasiparticle band with 4 meV dispersion observed

Hybridization gap confirmed by temperature-dependent spectroscopy

Hybridization strength in CeIn3 is weaker than in related compounds

Abstract

The electronic structure of the Kondo lattice CeIn3 has been studied by on-resonant angle-resolved photoemission spectroscopy and scanning tunneling microscopy/spectroscopy. A weakly dispersive quasiparticle band has been observed directly with an energy dispersion of 4 meV by photoemission, implying the existence of weak hybridization between the f electrons and conduction electrons. The hybridization is further confirmed by the formation of the hybridization gap revealed by temperature-dependent scanning tunneling spectroscopy. Moreover, we find the hybridization strength in CeIn3 is much weaker than that in the more two-dimensional compounds CeCoIn5 and CeIrIn5. Our results may be essential for the complete microscopic understanding of this important compound and the related heavy-fermion systems.