Related papers: On the crystal field in the modern solid-state the…
In many quantum magnets especially the rare-earth ones, the low-lying crystal field states are not well separated from the excited ones and thus are insufficient to describe the low-temperature magnetic properties. Inspired by this simple…
Processes occurring in the strong-field regime of QED are characterized by background electromagnetic fields of the order of the critical field $F_{cr}=m^2c^3/\hbar|e|$ in the rest frame of participating charges. It has been conjectured…
We apply the first-principles density functional theory + dynamical mean field theory framework to evaluate the crystal field splitting on rare earth sites in hard magnetic intermetallics. An atomic (Hubbard-I) approximation is employed for…
Neutron time-of-flight spectroscopy has been employed to study the crystal-field splitting of Pr$^{3+}$ in the pyrochlore stannate Pr$_{2}$Sn$_{2}$O$_{7}$. The crystal field has been parameterized from a profile fit to the observed neutron…
In a recent study of the magnetic properties of rare-earth systems the two extreme situations have been considered in which the crystalline electrostatic field is large or small with respect to the spin-orbit interaction. In the first case…
We present a crystal field theory of transition metal impurities in semiconductors in a trigonally distorted tetrahedral coordination. We develop a perturbative scheme to treat covalency effects within the weak ligand field case (Coulomb…
It has been shown that the crystal-field interactions can produce a non- magnetic singlet ground state for the highly-correlated d6 system situated in the quasi-octahedral crystal field (CEF) surrounding provided the spin-orbit interactions…
We introduce a phase-field crystal model that creates an array of complex three- and two-dimensional crystal structures via a numerically tractable three-point correlation function. The three-point correlation function is designed in order…
The existence of CEF states and the magnetism in conducting compounds NdAl2, UPd2Al3 and YbRh2Si2 is discussed. We point out that in metallic compounds localized crystal-field states coexist with conduction electrons. These compounds are…
Evidence is summarized attesting that the standard exchange field theory of ferromagnetism by Heisenberg has not been successful. It is replaced by the crystal field and a simple assumption that spin orientation is inexorably associated…
Rare-earth (RE) based compounds and alloys are of great interest both for their fundamental physical properties and for applications. In order to tailor the required compounds for a specific task, one must be able to predict the energy…
In a recent class of phase field crystal (PFC) models, the density order parameter is coupled to powers of its mean field. This effectively introduces a phenomenology of higher-order direct correlation functions acting on long wavelengths,…
On the basis of the point charge model, we formulate the crystalline electronic field (CEF) Hamiltonian $H_{\rm CEF}$ in the rare-earth based quasicrystal (QC) and approximant crystal (AC) with ligand ions located at pseudo 5-fold…
In materials science the phase field crystal approach has become popular to model crystallization processes. Phase field crystal models are in essence Landau-Ginzburg-type models, which should be derivable from the underlying microscopic…
As a possible mechanism of the $\gamma-\alpha$ phase transition in pristine cerium a change of the electronic density from a disordered state with symmetry Fm-3m to an ordered state Pa-3 has been proposed. Here we include on-site and inter-…
The choice that a solid system "makes" when adopting a crystal structure (stable or metastable) is ultimately governed by the interactions between electrons forming chemical bonds. By analyzing 6 prototypical binary transition-metal…
These are introductory lectures to some aspects of the physics of strongly correlated electron systems. I first explain the main reasons for strong correlations in several classes of materials. The basic principles of dynamical mean-field…
The ground state spin of the negatively charged nitrogen-vacancy center in diamond has been the platform for the recent rapid expansion of new frontiers in quantum metrology and solid state quantum information processing. In ambient…
Metal-insulator transitions driven by magnetic fields have been extensively studied in 2D, but a 3D theory is still lacking. Motivated by recent experiments, we develop a scaling theory for the metal-insulator transitions in the…
Exploring new parameter regimes to realize and control novel phases of matter has been a main theme in modern condensed matter physics research. The recent discovery of 2D magnetism in nearly freestanding monolayer atomic crystals has…