相关论文: Hund's coupling and electronic anisotropy in the s…
We study collective spin excitations of a magnetically ordered state in a multi-component system composed of both itinerant electrons and local moments. Here the induced spin-density-wave (SDW) ordering of itinerant electrons and the…
In order to numerically study electron correlation effects in multi-orbital systems, we propose a new type of discrete transformation for the exchange (Hund's coupling) and pair-hopping interactions to be used in the dynamical mean field…
We investigate the interplay of onsite Coulomb repulsion and various mechanisms breaking the fourfold lattice symmetry in a three-band model for the iron planes of iron-based superconductors. Using cluster-perturbation theory allows us to…
In this work, we investigate the microscopic origin of magnetism in $\mathrm{SrCoO_3}$ by incorporating electronic correlations within the dynamical mean-field theory (DMFT) framework. We note a remarkable agreement of the calculated…
We consider the Kondo-Hubbard model with ferromagnetic exchange coupling $% J_{H}$, showing that it is an approximate effective model for late transition metal-O linear systems. We study the dependence of the charge and spin gaps…
Multiorbital Hubbard models host strongly correlated 'Hund's metals' even for interactions much stronger than the bandwidth. We characterize this interaction-resilient metal as a mixed-valence state. In particular it can be pictured as a…
Previous work on the physical content of exchange correlation functionals that depend on both charge and spin densities is extended to elemental transition metals and a wider range of perovskite transition metal oxides. A comparison of…
In atomic physics, the Hund rule says that the largest spin and orbital state is realized due to the interplay of the spin-orbit coupling (SOC) and the Coulomb interactions. Here, we show that in ferromagnetic solids the effective SOC and…
We show that the conductivity of a two-dimensional electron gas can be intrinsically anisotropic despite isotropic Fermi surface, energy dispersion, and disorder configuration. In the model we study, the anisotropy stems from the interplay…
This article reviews the NMR and NQR studies on iron-based high-temperature superconductors by the IOP/Okayama group. It was found that the electron pairs in the superconducting state are in the spin-singlet state with multiple fully-opened…
Analysis of the band structure of TiS$_3$ single-layers suggests the possibility of changing their physical behaviour by injecting electron carriers. The anisotropy of the valence and conduction bands is explained in terms of their complex…
The two-orbital J1-J2 model that describes a square lattice of frustrated spin-1 iron atoms is analyzed within the linear spin-wave approximation and by exact diagonalization over a 4x4 cluster. A quantum critical point (QCP) is identified…
Recent neutron scattering studies revealed the three dimensional character of the magnetism in the iron pnictides and a strong anisotropy between the exchange perpendicular and parallel to the spin stripes. We extend studies of the J1-J2-Jc…
We discuss the role of electronic correlations in the iron-based superconductor LiFeAs by studying the effects on band structure, mass enhancements, and Fermi surface in the framework of density functional theory combined with dynamical…
The magnetic phase diagrams of models for quasi one-dimensional compounds belonging to the iron-based superconductors family are presented. The five-orbital Hubbard model and the real-space Hartree-Fock approximation are employed,…
Projector Quantum-Monte-Carlo Method is used to examine effects of the spin-independent $U_{fd}$ as well as spin-dependent $J_z$ Coulomb interaction between the localized $f$ and itinerant $d$ electrons on the stability of various types of…
We study a two-dimensional single band Hubbard Hamiltonian with antisymmetric spin-orbit coupling. We argue that this is the minimal model to understand the electronic properties of locally non-centrosymmetric transition-metal (TM) oxides…
We investigate a possibility of Hund's metal behavior in the Hubbard model with asymmetric density of states having peak(s). Specifically, we consider the degenerate two-band model and compare its results to the five-band model with…
We systematically investigate the stability of the symmetry-protected topological (SPT) Haldane phase in spin-1/2 Heisenberg and half-filled Hubbard ladders coupled by ferromagnetic Hund's interactions. Using density-matrix renormalization…
We present analytical and numerical investigation of spectral and transport properties of a quadruple quantum-dot (QQD) structure which is one of the popular low-dimensional systems in the context of fundamental quantum physics study,…