Evolution of the Fermi Surface across a Magnetic Order-Disorder Transition in the Two-Dimensional Kondo Lattice Model: A Dynamical Cluster Approach

TL;DR

This study investigates how the Fermi surface evolves across magnetic phase transitions in a 2D doped Kondo lattice model using a dynamical cluster approximation, revealing changes from heavy fermion bands to spin-density wave-like Fermi surfaces.

Contribution

It provides a detailed dynamical cluster analysis of the Fermi surface evolution across magnetic transitions in the 2D Kondo lattice model, highlighting the persistence of Kondo screening.

Findings

Heavy fermion band structure with large Luttinger volume in paramagnetic phase

Fermi surface topology changes to hole pockets in antiferromagnetic phase

Kondo screening persists without breakdown across the transition

Abstract

We use the dynamical cluster approximation, with a quantum Monte Carlo cluster solver on clusters of up to 16 orbitals, to investigate the evolution of the Fermi surface across the magnetic order-disorder transition in the two-dimensional doped Kondo lattice model. In the paramagnetic phase we observe the generic hybridized heavy fermion band structure with large Luttinger volume. In the antiferromagnetic phase, the heavy fermion band drops below the Fermi surface giving way to hole pockets centered around k=(pi/2,pi/2) and equivalent points. In this phase Kondo screening does not break down but the topology of the resulting Fermi surface is that of a spin-density wave approximation in which the localized spins are frozen.