Coherence scale of the two-dimensional Kondo Lattice model

TL;DR

This study uses quantum Monte Carlo simulations to explore the coherence scale in the two-dimensional Kondo lattice model, revealing that the quasiparticle residue and effective mass are closely linked to the Kondo temperature, with implications for understanding charge carrier behavior.

Contribution

It demonstrates that the quasiparticle residue tracks the Kondo scale in the 2D Kondo lattice model, connecting the coherence temperature to the single impurity Kondo temperature.

Findings

Doped hole momentum is (pi, pi) regardless of J/t.

Quasiparticle residue Z_{(, )} tracks the Kondo temperature T_K.

Effective mass at the Fermi level is proportional to 1/T_K.

Abstract

A doped hole in the two-dimensional half-filled Kondo lattice model with exchange J and hopping t has momentum (pi,pi) irrespective of the coupling J/t. The quasiparticle residue of the doped hole, Z_{(\pi, \pi)}, tracks the Kondo scale, T_K, of the corresponding single impurity model. Those results stem from high precision quantum Monte Carlo simulations on lattices up to 12 X 12. Accounting for small dopings away from half-filling within a rigid band approximation, this result implies that the effective mass of the charge carriers at the Fermi level tracks 1/T_K or equivalently that the coherence temperature T_{coh} \propto T_K. This results is consistent with the large-N saddle point of the SU(N) symmetric Kondo lattice model.