Heavy Quasiparticles in the Anderson Lattice Model

TL;DR

This paper uses exact diagonalization to study the one-dimensional Anderson lattice model, revealing the formation of heavy quasiparticles driven by low-energy spin excitations, contrasting with the hybridization picture.

Contribution

It demonstrates that low-energy spin excitations are crucial for heavy quasiparticle formation, challenging the traditional hybridization-based understanding.

Findings

Reproduces key features of an infinite Kondo lattice

Identifies the role of spin excitations in quasiparticle formation

Shows nearly localized low-energy bands of heavy quasiparticles

Abstract

An exact-diagonalization technique on small clusters is used to study the dynamics of the one-dimensional symmetric Anderson lattice model. Our calculated excitation spectra reproduce key features expected for an infinite Kondo lattice such as nearly localized low-energy spin excitations and extended regions of `heavy-quasiparticle' bands. We show that, in contrast to the hybridization picture, low-energy spin excitations of the nearly-localized $f$-electron system play a key role in the formation of an almost dispersionless low-energy band of heavy quasiparticles.