Emergent Coherent Lattice Behavior in Kondo Nanosystems

TL;DR

This study uses quantum Monte Carlo simulations to determine how many magnetic moments arranged on a metallic surface are needed to form a coherent Kondo lattice, revealing the emergence of heavy-fermion bands and hybridization gaps.

Contribution

It demonstrates how magnetic shells induce coherent Kondo lattice behavior and identifies the transition from local Kondo physics to collective heavy-fermion states.

Findings

Fast splitting of Kondo resonance with added magnetic shells

Formation of composite heavy-fermion bands

Hybridization gap correlates with antiferromagnetic correlations

Abstract

How many magnetic moments periodically arranged on a metallic surface are needed to generate a coherent Kondo lattice behavior? We investigate this fundamental issue within the particle-hole symmetric Kondo lattice model using quantum Monte Carlo simulations. Extra magnetic atoms forming closed shells around the initial impurity induce a fast splitting of the Kondo resonance at the inner shells which signals the formation of composite heavy-fermion bands. The onset of the hybridization gap matches well the enhancement of antiferromagnetic spin correlations in the plane perpendicular to the applied magnetic field, a genuine feature of the coherent Kondo lattice. In contrast, the outermost shell remains dominated by a local Kondo physics with spectral features resembling the single-impurity behavior.