Related papers: Effective three-band model for double perovskites
Multi-orbital Hubbard model Hamiltonians for the undoped parent compounds of the Fe-pnictide superconductors are here investigated using mean-field techniques. For a realistic four-orbital model, our results show the existence of an…
We present a comprehensive theory of the temperature- and disorder-dependence of half-metallic ferrimagnetism in the double perovskite Sr$_2$FeMoO$_6$ (SFMO) with $T_c$ above room temperature. We show that the magnetization $M(T)$ and…
The double perovskite material \SFMO has the rare and desirable combination of a half-metallic ground state with 100% spin polarization and ferrimagnetic \Tc$\simeq 420$K, well above room temperature. In this two-part paper, we present a…
We present a microscopic theory of carrier-induced ferrimagnetism in metallic double perovskite compounds such as ${\rm Sr}_{2}{\rm FeMoO}_{6}$ and ${\rm Sr}_{2}{\rm FeReO}_{6}$ which have recently attracted intense interest for their…
We study by dynamical mean field theory the ground state of a quarter-filled Hubbard model of two bands with different bandwidths. At half-filling, this model is known to display an orbital selective Mott transition, with the narrower band…
Transition metal dichalcogenide superlattices provide an exciting new platform for exploring and understanding a variety of phases of matter. The moir\'e continuum Hamiltonian, of two-dimensional jellium in a modulating potential, provides…
The three-band Hubbard model is a fundamental model for understanding properties of the Copper-Oxygen planes in cuprate superconductors. We use cutting-edge auxiliary-field quantum Monte Carlo (AFQMC) methods to investigate ground state…
The title material has a quasi-one-dimensional electronic structure and is of considerable interest because it has a metallic phase with properties different from a simple Fermi liquid, a poorly understood "insulating" phase, and a…
Motivated by recent Fermi surface and transport measurements on LaNiO3, we study the Mott Metal-Insulator transitions of perovskite nickelates, with the chemical formula RNiO3, where R is a rare-earth ion. We introduce and study a minimal…
The Mott metal-insulator transition in the two-band Hubbard model in infinite dimensions is studied by using the linearized dynamical mean-field theory. The discontinuity in the chemical potential for the change from hole to electron doping…
Based on experimental data on the newly synthesized iron-based superconductors and the relevant band structure calculations, we propose a minimal two-band BCS-type Hamiltonian with the interband Hubbard interaction included. We illustrate…
Transition-metal perovskite oxides constitute a series of functional material systems for electronics, catalysis and energy-conversion processes, in which oxygen migration and evolution play a key role. However, the stable metal-oxygen…
A three-band model for copper oxides in the region of parameters where the second hole on the copper has energy close to the first hole on the oxygen is considered. The exact solution for one hole on a ferromagnetic background of the…
We investigate the Mott transitions in two-orbital Hubbard systems. Applying the dynamical mean field theory and the self-energy functional approach, we discuss the stability of itinerant quasi-particle states in each band. It is shown that…
The intraband electromagnetic transitions in the framework of collective Hamiltonian for chiral and wobbling modes are calculated. By going beyond the mean field approximation on the orientations of rotational axis, the collective…
We investigate the ground state phase diagram of the half-filled $t-t^{\prime}$ repulsive Hubbard model in the presence of a staggered ionic potential $\Delta$, using the continuum-limit bosonization approach. We find, that with increasing…
The band inversion transition in a cylindrical HgTe nanowire is inducible via varying the nanowire radius. Here we derive the low-energy effective Hamiltonian describing the band structure of the HgTe nanowire close to the fundamental band…
Using the first-principles density functional approach, we investigate Ca$_2$FeOsO$_6$, a material of double perovskite structure synthesized recently. According to the calculations, Ca$_2$FeOsO$_6$ is a ferrimagnetic Mott-insulator…
We analyze the electronic properties of interacting crystal field split three band systems. Using a rotationally invariant slave boson approach we analyze the behavior of the electronic mass renormalization as a function of the intralevel…
We characterize the low-energy physics of the two-orbital Hubbard model in the orbital-selective Mott phase, in which one band is metallic and the other insulating. Using dynamical mean-field theory with the numerical renormalization group…