Formation of a Heavy-Fermion State in the 2D Periodic Anderson Model

TL;DR

This paper investigates the emergence of heavy-fermion behavior in a 2D periodic Anderson model, revealing how electron interactions lead to Kondo screening or magnetic instability depending on the interaction strength.

Contribution

It provides a detailed analysis of how varying Coulomb interaction U influences the formation of heavy-fermion states and magnetic order in the 2D periodic Anderson model.

Findings

At U=2, Kondo screening leads to a heavy-fermion state.

At U=3 and 4, RKKY interaction causes magnetic instability.

Partial screening results in a sharp density of states peak.

Abstract

We study the formation of a heavy-fermion state in the 2D periodic Anerson model. For U=2, the density of states, imaginary part of the self-energy and effective magnetic moment all indicate the Kondo screening of local f electrons, leading to a coherent heavy-fermion state. For U=3 and 4, the dominance of RKKY interaction over Kondo screening at low temperatures indicates a magnetic instability at zero temperature. A partial screening of magnetic moments, however, still gives rise to a relatively sharp peak at the Fermi energy in the density of states.