Dynamic correlations in doped 1D Kondo insulator: Finite-T DMRG study

TL;DR

This study uses finite-temperature DMRG to analyze dynamic correlations in a 1D doped Kondo insulator, revealing pseudogap formation and collective excitations indicative of Tomonaga-Luttinger liquid behavior.

Contribution

It applies finite-T DMRG to compute dynamic correlations in the 1D Kondo lattice model, providing new insights into low-temperature collective excitations and pseudogap phenomena.

Findings

Pseudogap develops below the crossover temperature near half filling.

A sharp zero-frequency peak indicates collective excitations.

The metallic phase exhibits Tomonaga-Luttinger liquid characteristics at low temperatures.

Abstract

The finite-T DMRG method is applied to the one-dimensional Kondo lattice model to calculate dynamic correlation functions. Dynamic spin and charge correlations, S_f(omega), S_c(omega), and N_c(omega), and quasiparticle density of states rho(omega) are calculated in the paramagnetic metallic phase for various temperatures and hole densities. Near half filling, it is shown that a pseudogap grows in these dynamic correlation functions below the crossover temperature characterized by the spin gap at half filling. A sharp peak at omega=0 evolves at low temperatures in S_f(omega) and N_c(omega). This may be an evidence of the formation of the collective excitations, and this confirms that the metallic phase is a Tomonaga-Luttinger liquid in the low temperature limit.