Related papers: Heavy Fermion-like metal alpha double prime-Fe16N2…
A new model is proposed for the strong ferromagnetism associated with partially localized orbitals in the Fe16N2 metallic system which draws substantially from models of heavy fermion metals. The basic idea is that the spatially isolated…
The mystery of giant saturation magnetization of Fe16N2 has remained for 37 years. In this letter, X-ray absorption spectroscopy (XAS) and magnetic circular dichroism (XMCD) are used to study the electron states of Fe atoms in Fe16N2 and…
We examine the mystery of the disputed high-magnetization \alpha"-Fe16N2 phase, employing the Heyd-Scuseria-Ernzerhof screened hybrid functional method, perturbative many-body corrections through the GW approximation, and onsite Coulomb…
Strong electron correlations lie at the origin of transformative phenomena such as colossal magneto-resistance and high-temperature superconductivity. Already near room temperature, doped copper oxide materials display remarkable features…
A consistent picture on the mean-field level of the magnetic properties and electronic structure of the superconducting itinerant ferromagnet UGe$_2$ is shown to require inclusion of correlation effects beyond the local density…
The compound FeMnP$_{0.50}$Si$_{0.50}$ has been studied by magnetic measurements, M\"ossbauer spectroscopy and electronic structure and total energy calculations. An unexpected high magnetic hyperfine field for Fe atoms located at the…
We consider a model of the double perovskite Ba2FeReO6, a room temperature ferrimagnet with correlated and spin-orbit coupled Re t2g electrons moving in the background of Fe moments stabilized by Hund's coupling. We show that for such 3d/5d…
The total spin of the ground state is calculated in the U -> infinity Hubbard model with uniform magnetic flux perpendicular to a square lattice, in the absence of Zeeman coupling. It is found that the saturated ferromagnetism emerges in a…
The first-principles full-potential linearized augmented plane-wave method based on density functional theory is used to investigate electronic structure and magnetic properties of hypothetical binary compounds of I$^{A}$ subgroup elements…
We numerically study quantum magnetism of ultra-cold alkali and alkaline-earth fermion systems with large hyperfine spin $F=3/2$, which are characterized by a generic $Sp(N)$ symmetry with N=4. The methods of exact diagonalization (ED) and…
Correlations between the localized and conductive spins/charges have been the central issue of various fascinating quantum phenomena found on itinerant electron systems. Here, the obvious multiplet structures are presented on the Mn 2$p$ to…
We report intrinsic ferromagnetism in monolayer electrides or electrenes, in which excess electrons act as anions. Our first-principles calculations demonstrate that magnetism in such electron-rich two-dimensional (2D) materials originates…
In this letter, we address a novel mechanism for iron based superconductors. We study $F^{2+}$ state of iron with six 3d electrons. Five of them are localized with ferromagnetic order, while the sixth one is itinerant antiparallel with the…
Heavy Fermion physics deals with the ground state formation and interactions in f-electron materials where the electron effective masses are extremely large, more than 100 times the rest mass of an electron. The details of how the…
These three metallic systems do not exhibit any magnetic ordering despite experiments show the existence of localized moments with large antiferromagnetic exchange: this is a consequence of the strong geometric frustration (Y(Sc)Mn_{2} and…
Using spin density functional theory we have carried out a comparative study of chemical bonding and magnetism in Fe_4N, Fe_3N and Fe_2N. All of these compounds form close packed Fe lattices, while N occupies octahedral interstitial…
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…
Metallic magnetism is both ancient and modern, occurring in such familiar settings as the lodestone in compass needles and the hard drive in computers. Surprisingly, a rigorous theoretical basis for metallic ferromagnetism is still largely…
Theoretical model for magnetic ordering in the heavy-fermion metal URu2Si2 is suggested. The 17.5K transition in this material is ascribed to formation of a spin-density wave, which develops due to a partial nesting between electron and…
We study the formation of a heavy-fermion state in the 2D periodic Anerson model. For U=2, the density of states, imaginary part of the self-energy and effective magnetic moment all indicate the Kondo screening of local f electrons, leading…