Physical review. B, Condensed matter
Influence of hybridization on ground-state properties of the Falicov-Kimball model
Pavol Farkašovský
Abstract
The density matrix renormalization group and small cluster exact diagonalization calculations are used to examine ground-state properties of the Falicov-Kimball model in one and two dimensions. Particular attention is paid to hybridization effects on insulator-metal transitions. The nature of the ground state is analyzed through the behavior of the single-particle excitation energy and the f and d electron density of states. A number of remarkable results are found. (i) At zero hybridization the gaps in the f and d electron density of states do not coincide, and almost all f electron spectral weight is located outside the d electron subbands. (ii) For nonzero hybridization the f and d electron gaps coincide, for both the symmetric and unsymmetric case. (iii) No insulator-metal transitions driven by hybridization are found in one as well as in two dimensions.