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

The finite-T DMRG method is applied to the one-dimensional Kondo lattice mo del to calculate dynamic correlation functions. Dynamic spin and charge cor relations, S-f(omega), S-c(omega), and N-e(omega), and quasiparticle densit y of states rho(omega) are calculated in the paramagnetic metallic phase fo r various temperatures and hole densities. Near half filling, it is shown t hat a pseudogap grows in these dynamic correlation functions below the cros sover temperature characterized by the spin gap at half filling. A sharp pe ak at omega = 0 evolves at low temperatures in S-f(omega) and N-c(omega). T his may he evidence of the formation of collective excitations, and this co nfirms that the metallic phase is a Tomonaga-Luttinger liquid in the low-te mperature limit.