Related papers: Low density approach to the Kondo-lattice model
Single-particle spectrum of the Kondo lattice model is derived with use of the continuous-time quantum Monte Carlo method, combined with the dynamical mean-field theory. Crossover behavior is traced quantitatively either to a heavy…
The two-channel Kondo lattice model is examined with a Quantum Monte Carlo simulation in the limit of infinite dimensions. We find non-fermi-liquid behavior at low temperatures including a finite low-temperature single-particle scattering…
We present a high temperature series expansion for the ferromagnetic Kondo lattice model in the large coupling limit, which is used to model CMR perovskites. Our results show the expected cross-over to Curie-Wei{\ss} behavior at a…
We establish the low-temperature phase diagrams of the spin-1/2 and spin-1 Kondo lattice models as a function of the conduction-band filling n and the exchange coupling strength J in the regime of ferromagnetic effective exchange…
In our recent study, Phys. Rev. Lett. 108 086402 (2012), we have revealed the intriguing properties of the ferromagnetic state in the Kondo lattice model with antiferromagnetic coupling in infinite dimensions: within the ferromagnetic…
We study the low energy properties of the one-orbital quantum double-exchange model by using the slave fermion formulation. We construct a mean-field theory which gives a simple explanation for the magnetic and thermodynamic properties of…
We investigate a Kondo lattice model with correlated conduction electrons. Within dynamical mean-field theory the model maps onto an impurity model where the host has to be determined self-consistently. This impurity model can be derived…
We propose a modified RKKY-technique to evaluate the magnetic properties of the ferromagnetic Kondo-lattice model. Together with a previously developed selfenergy approach to the conduction electron part of the model we get a closed system…
The double-exchange model, which has been extensively studied in the context of colossal magneto-resistance in perovskite manganese oxides, is known to exhibit a ferromagnetic metallic state at low temperatures because of the interplay…
The nature of superconductivity in heavy-fermion materials is a subject under intense debate, and controlling this many-body state is central for its eventual understanding. Here, we examine how proximity effects may change this phenomenon,…
The phase diagram of the Kondo lattice Hamiltonian with ferromagnetic Hund's coupling in the limit where the spin of the localized $t_{2g}$ electrons is classical is analyzed in one dimension as a function of temperature, electronic…
An exact-diagonalization technique on small clusters is used to study the dynamics of the one-dimensional symmetric Anderson lattice model. Our calculated excitation spectra reproduce key features expected for an infinite Kondo lattice such…
A theoretical study of magnetic field (h) effects on single-particle spectra and transport quantities of heavy fermion metals in the paramagnetic phase is carried out. We have employed a non-perturbative local moment approach (LMA) to the…
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.…
With a mean field approach, the heavy Fermi liquid in the two-dimensional Kondo lattice model is carefully considered in the presence of short-range antiferromagnetic correlations. As the ratio of the local Heisenberg superexchange coupling…
We describe the transition from a ferromagnetic phase, to a disordered para- magnetic phase, which occurs in one-dimensional Kondo lattice models with partial conduction band filling. The transition is the quantum order-disorder transition…
Coexistence between ferromagnetic order and Kondo behavior has been observed in some uranium compounds. The underscreened Kondo lattice model can provide a possible description of this coexistence. Here we present a model of a lattice of…
A tight-band model is employed for the $e_{2g}$-orbitals in manganites. It is shown that a large intraatomic Hund's coupling, $J_H$ and the resulting double-exchange mechanism lead to antiferromagnetic ordering along one of the cubic axis…
We study the low-temperature properties of a Kondo lattice using the large-N formalism. For a singular density of conduction states (DOS), we generalize the single-impurity result of Withoff and Fradkin: the strong-coupling fixed point…
Effective models are derived from the ferromagnetic Kondo lattice model with classical corespins, which greatly reduce the numerical effort. Results for these models are presented. They indicate that double exchange gives the correct order…