On the stability of charge and spin order in the spin-one-half Falicov–Kimball model with the Ising-type Hund coupling

Abstract

Density matrix renormalization group (DMRG) method is used to study effects of various factors on the stability of charge and spin order in the spin-one-half Falicov–Kimball model with the Ising-type Hund coupling Jz. In particular we examine effects of (i) the exchange interaction (J) between d and f electrons, which is responsible for spin-flip processes, (ii) the f-electron hopping (tf) and (iii) the interband d–f hybridization V. It is shown that for all mentioned generalizations there exists some critical value of the exchange interaction (Jc), the f-electron hopping (tfc) and the interband d–f hybridization Vc at which the magnetic order detected within the spin-one-half Falicov–Kimball model with the Ising interaction is broken. Above these critical points new types of spin orderings are generated, and namely, spin density waves commensurate with charge density waves detected at J=0 in the case of exchange interaction and spin separated phases in the case of f-electron hopping (hybridization), which are at sufficiently large tf (V) replaced by homogeneous phases.