Related papers: Ferromagnetism in Electronic Models for Manganites
Ferromagnetic (FM) manganites, a group of likely half-metallic oxides, are of special interest not only because they are a testing ground of the classical doubleexchange interaction mechanism for the colossal magnetoresistance, but also…
The quantum mechanical ground state of a 2D $N$-electron system in a confining potential $V(x)=Kv(x)$ ($K$ is a coupling constant) and a homogeneous magnetic field $B$ is studied in the high density limit $N\to\infty$, $K\to \infty$ with…
We study the competition between different possible ground states of the double-exchange model with strong ferromagnetic exchange interaction between itinerant electrons and local spins. Both for classical and quantum treatment of the local…
Recently, a novel collinear magnet, i.e. the altermagnet (AM), with spin-splitting energy band and zero net magnetization have attracted great interest due to its potential spintronic applications. Here, we demonstrate AM-like phases in a…
We investigate metamagnetic transitions in models for heavy fermions by considering the doped Kondo lattice model in two dimensions. Results are obtained within the framework of dynamical mean field and dynamical cluster approximations.…
A "minimal model" of the Kondo-lattice type is used to describe a competition between the localization and metallicity in doped manganites and related magnetic oxides with Jahn-Teller ions. It is shown that the number of itinerant charge…
In this paper, we prove that the ground state of the Kondo model with large spin is nondegenerate, apart from a SU(2) spin degeneracy in the case of half filling. The ground state spin is found for the system, and the energy level orderings…
The 2D ferromagnetic Kondo model with classical corespins is studied for a hole doping up to x = 0.125 via unbiased Monte Carlo (MC) simulations. A canonical algorithm for finite temperatures is developed. We show that with realistic…
Using ab initio band structure and model calculations we studied magnetic properties of one of the Mn$_4$ molecular magnets (Mn4(hmp)6), where two types of the Mn ions exist: Mn3+ and Mn2+. The direct calculation of the exchange constants…
We study higher-spin ($S \geq 1$) generalization of the one-dimensional Kondo-Heisenberg model, in which the local spin-$S$ moments of the Kondo lattice model interact with each other via the antiferromagnetic Heisenberg interaction…
I briefly survey here attempts to model the rich and strange behaviour of colossal magnetoresistance manganites, after outlining some of the phenomena observed in them, and describing the three relevant strong local interactions of the e_g…
A new minimal model is constructed for the doped manganese oxides which exhibit colossal magnetoresistance (CMR), involving broad spin-majority conduction band as well as nearly localised spin-minority electron states. A simple mean field…
We analyze a system composed of itinerant electrons and localized spins with on-site interactions representing the Hund's first rule. Properties of the system are studied rigorously on the infinite square lattice but the configurational…
We studied ferromagnetism in the one-dimensional Hubbard model with doubly degenerate atomic orbitals by means of the density-matrix renormalization-group method and obtained the ground-state phase diagrams. It was found that ferromagnetism…
Using the Density Matrix Renormalization Group, we study metallic ferromagnetism in a one-dimensional copper-oxide model which contains one oxygen p-orbital and one copper d-orbital. The parameters for the d-p model can be chosen so that it…
We consider a two-dimensional quantum spin system described by a Heisenberg model that is embedded in a three-dimensional metal. The two systems couple via an antiferromagnetic Kondo interaction. In such a setup, the ground state…
We consider a Kondo impurity coupled to a fermionic host with a power-law density of states near the Fermi level, rho(epsilon) ~ |epsilon|^r, with exponent r<0. Using both perturbative renormalization group (poor man's scaling) and…
We study the ground-state properties of an extended periodic Anderson model to understand the role of Hund's coupling between localized and itinerant electrons using the density-matrix renormalization group algorithm. By calculating the von…
The ferromagnetic Kondo model with classical corespins is studied via unbiased Monte-Carlo simulations. We show that with realistic parameters for the manganites and at low temperatures, the double-exchange mechanism does not lead to phase…
We compute the magnetic structure factor, the singlet correlation function and the momentum distribution of the one-dimensional Kondo lattice model at the density $\rho =0.7$. The density matrix-renormalization group method is used. We show…