The one-dimensional Kondo lattice model studied by thedensity matrix renormalization group method

Abstract

We have found an error in the calculation of imaginary-time one-particle Green's functions G() by the finite-temperature density-matrix renormalization-group (finite-T DMRG) method. The problem is concerned with the counting of the Fermionic sign; the two-particle correlation functions were calculated correctly. Although the main conclusions do not change, the one-particle Green's functions G() shown in figure 18 and the density of states shown in figures 19 and 20 should be replaced by these given here. The gap edge of the spectrum at the lowest temperature is not modified. The spectra have intensities in the region ||3, which is reduced considerably from the original results. However, the spectral weight extends beyond the original band width and the reason for that remains the same: the exchange interaction between the conduction electrons and the f spins. The important conclusion about the temperature dependence of the spectrum also remains the case. With increasing temperature, the low-frequency structure varies drastically at much lower temperature than qp = 0.7t, and the gap structure disappears at T0.3t. Figure 18. Imaginary-time correlation functions, G(), of the half-filled one-dimensional Kondo lattice model; J/t = 1.6. The Trotter number M = 80 for T/t = 0.1 and 50 for T/t = 0.2,0.3,0.4. The inset shows the results for different numbers of states, m, retained in the DMRG calculations. The truncation errors in the DMRG calculations are 3 × 10-3 for m = 26 and 8 × 10-4 for m = 50 at T/t = 0.2. Figure 19. The quasiparticle density of states, (), obtained from G() by using the Padé approximants and the maximum-entropy method (MEM); J/t = 1.6.Figure 20. The quasiparticle density of states, (), of the half-filled one-dimensional Kondo lattice model; J/t = 1.6. The number of states, m, retained in the DMRG calculations is 50.