Atomic and Electronic Structures of the Monolayer Kondo Lattice CePt₂/Pt(111)

Abstract

We study the atomic and electronic structures of the monolayer Kondo lattice CePt₂/Pt(111) using scanning tunneling microscopy/spectroscopy (STM/STS). A monolayer (2×2)-CePt₂ is formed by depositing Ce atoms on Pt(111) and annealing at 720 K. Atomically resolved STM images reveal that the monolayer (2×2)-CePt₂ is protected by a chemically inert topmost Pt₄ layer. The quasiparticle interference (QPI) measured on the (2×2) structure indicates a Shockley-type surface state similar to that on Pt(111) with a downward shift due to charge transfer from the underneath CePt₂ layer. We discuss a possible two-dimensional coherent Kondo effect (heavy fermion) with the observed STS spectra.