Problems of strongly interacting electrons can be greatly simplified by reducing them to effective quantum spin models. The initial step is renormalization of the Hamiltonian into a lower energy subspace. The positive and negative U Hubbard models are explicitly transformed into the Heisenberg and -x-xz models respectively. Basic tools of quantum magnetism are introduced and used: spin coherent...

High-valent transition-metal-substituted Keggin-type polyoxometalates (POMs) are active and robust oxidation catalyst. The important oxidized intermediates of these POM complexes are very difficult to be characterized by using the experimental method, and thus no detail information is available on such species. In the present paper, density functional theory (DFT) calculations have been carried...

the entanglement at zero-temperature is studied in a two-qubit xz spin-1/2 chain model in anexternal magnetic field which is applied in the z direction. we have obtained an analytical relation forthe effect of the external magnetic field on the concurrence. it is shown that the ground state of thesystem depends on the strength of exchange coupling. we have shown that the analytical relation oft...

We report the results of a series of density functional theory (DFT) calculations aimed at predicting the (57)Fe Mössbauer electric field gradient (EFG) tensors (quadrupole splittings and asymmetry parameters) and their orientations in S = 0, (1)/(2), 1, (3)/(2), 2, and (5)/(2) metalloproteins and/or model systems. Excellent results were found by using a Wachter's all electron basis set for iro...

In this paper, we extend our previous work in investigating the performance of XZ-shape histogram for recognizing human performing activities of daily living (ADLs) which focuses on human-object interaction activities based on Kinect-like depth image. The feasibility of XZ-shape histogram as well as general 3D shape descriptors namely; 1) shape distribution, 2) shape histogram, 3) global spin i...

We use neutron scattering to study spin excitations in single crystals of LiFe_{0.88}Co_{0.12}As, which is located near the boundary of the superconducting phase of LiFe_{1-x}Co_{x}As and exhibits non-Fermi-liquid behavior indicative of a quantum critical point. By comparing spin excitations of LiFe_{0.88}Co_{0.12}As with a combined density functional theory and dynamical mean field theory calc...

We report on multi-epoch HST/WFPC2 images of the XZ Tauri binary, and its outflow, covering the period from 1995 to 2001. Data from 1995 to 1998 have already been published in the literature. Additional images, from 1999, 2000 and 2001 are presented here. These reveal not only further dynamical and morphological evolution of the XZ Tauri outflow but also that the suspected outflow source, XZ Ta...

Transition metal monosilicides CoSi, CoGe, RhSi, and RhGe in the chiral cubic B20 structure (the CoSi family) have recently been found to host unconventional fermions beyond spin-1/2 Weyl fermions, also exhibit exotic physical phenomena such as long Fermi arc surface states, gyrotropic magnetic effect, quantized circular photogalvanic effect. Thus, exploring novel spin-related transports these ...

Using a three-band Hubbard Hamiltonian we calculate within the random-phase approximation the spin susceptibility, x(q,v), and nuclear magnetic resonance spin-lattice relaxation rate, 1/T1, in the normal state of the triplet superconductor Sr2RuO4 and obtain quantitative agreement with experimental data. Most importantly, we find that due to spin-orbit coupling the out-of-plane component of the...

Perpendicular magnetic anisotropy of the new ferromagnetic semiconductor (Ba,K)(Zn,Mn)$_{2}$As$_{2}$ is studied by angle-dependent x-ray circular dichroism measurements. The large with field 0.85 T deduced fitting Stoner-Wohlfarth model to magnetic-field-angle dependence projected moment. Transverse XMCD spectra highlights anisotropic distribution Mn 3$d$ electrons, where $d_{xz}$ and $d_{yz}$ ...