The Gilbert damping constant present in the phenomenological Landau-Lifshitz-Gilbert equation describing dynamics of magnetization is calculated for ferromagnetic metallic films as well Co/nonmagnet (NM) bilayers. calculations are done within a realistic nine-orbital tight-binding model including spin-orbit coupling. convergence expressed sum over Brillouin zone remarkably improved by introducing finite temperature into electronic occupation factors and subsequent summation Matsubara...

The magnetocrystalline anisotropy (MA) of ferromagnetic fcc Ni, Co, and bcc Fe (001) slabs is calculated to second order in the spin-orbit coupling constant using realistic tight-binding models with parameters fitted available first-principles electronic-structure calculations. Results for 1--17 atomic layers show that MA favors magnetization perpendicular slab but in-plane Ni agreement experiment. Fluctuations as thickness varied indicate surface not purely local origin layer.

Magnetic anisotropy depends strongly on the density of states at Fermi level. If significant contributions to magnetocrystalline energy (MAE) are due spin-polarized quantum well (QWS), a increase MAE can occur periodically as function film thickness. The oscillation period L is determined by wavelength corresponding electron waves. uniaxial magnetic fcc-Co found oscillate with 2.3 ML. In contrast, in bcc-Fe, oscillates 5.9 We attribute such oscillations QWS minority-spin d-band

The effect of electron confinement on the magnetocrystalline anisotropy ultrathin bcc Fe films is explored by combining photoemission spectroscopy, x-ray magnetic circular dichroism, and magneto-optical Kerr measurements. Pronounced thickness-dependent variations in are ascribed to periodic changes density states at Fermi level, induced quantization ${d}_{xz}$, ${d}_{yz}$ out-of-plane orbitals. Our results reveal a direct correlation between quantum well states, orbital moment, anisotropy.

Magnetocrystalline anisotropy (MA) energy of (001) face-centred-cubic Co(N) films is calculated for film thicknesses N = 1–28 in a realistic tight-binding model with and without sp–d orbital hybridization included. The obtained results show that the average MA not largely influenced by hybridization. On other hand, oscillation pattern remarkably changed when included: this case has oscillations clear period 2 atomic layers (AL), similar to previous ab initio calculations (Szunyogh L,...

The Gilbert damping constant in the phenomenological Landau-Lifshitz-Gilbert equation which describes dynamics of magnetization, is calculated for Fe, Co and Ni bulk ferromagnets, films Co/Pd bilayers within a nine-band tight-binding model with spin-orbit coupling included. calculational effciency remarkably improved by introducing finite temperature into electronic occupation factors subsequent summation over Matsubara frequencies. dependence on scattering rate good agreement results...

We present quantum mechanical calculations of the Gilbert damping constant $\ensuremath{\alpha}$ in ultrathin ${\mathrm{L}1}_{0}$ ${[\mathrm{Co}/\mathrm{NM}]}_{N}$ superlattices and (001) fcc magnetic multilayers built cobalt nonmagnetic metals NM = Cu, Ag, Pd, Pt, Au. The are performed within a realistic nine-orbital tight-binding model band structure including spin-orbit interaction. dependence on stacking number $N$, ferromagnetic layer thicknesses as well electron scattering rate is...

Abstract The Hartree–Fock (HF) equation for atoms with closed (sub)shells is transformed the pseudospectral (PS) method into a discrete eigenvalue scaled orbitals on finite radial grid. Fock exchange operator and Hartree potential are obtained from respective Poisson equations also discretized using PS representation. numerical solution of HF closed-(sub)shell He to No robust, fast gives extremely accurate results, accuracy superior that previous calculations. A very moderate number 33 71...

Magnetocrystalline anisotropy (MCA) energy and the of orbital magnetic moment (AOM), relations between them, methods their calculation are investigated for (001) fcc Co film $\mathrm{Co}/X$ bilayers ($X=\mathrm{Pd}$ Pt), using a realistic tight-binding model. The derived by Bruno [Phys. Rev. B 39, 865 (1989)] van der Laan [J. Phys.: Condens. Matter 10, 3239 (1998)], including AOM only, found to give largely incorrect mean values MCA but reproduce its oscillatory variation versus thickness,...

Magnetocrystalline anisotropy (MA) constants are calculated for numerous Ni(m), Co(m), Co(m)/Pd(p)/Co(m), Pd(p)/Co(m)/Pd(p) (001) and (110) fcc slabs using a realistic tight-binding model. Perpendicular MA an Co/Pd interface is predicted in agreement with experimental data other theoretical calculations. broken down into contributions coming from various k points the two-dimensional Brillouin zone or atomic layers slab. It visualized that originates mostly regions around surfaces interfaces...

Three approximate exchange potentials of high accuracy ${v}_{\mathrm{x}}^{\mathrm{Y}}(\mathbf{r})$, $\mathrm{Y}=\mathrm{A}$,B,C, for the density-functional theory applications are obtained by replacing matrix elements exact potential between Kohn-Sham (KS) orbitals with such Fock operator (within virtual-occupied subset only) in three representations found any local potential. A common identity is base these representations. The ${v}_{\mathrm{x}}^{\mathrm{C}}$ happens to be same as that...

The effect of quantum well states (QWS) formed in a Cu overlayer on the magnetic anisotropy Fe and Co films underneath is investigated at low temperatures. An oscillatory observed below 50 K, with period ${L}_{Cu}=5.8$ ML, it same for Cu/Fe Cu/Co. We attribute this to QWS from $\mathit{sp}$ electrons which hybridize $d$ Fermi level (and Co) thus modify This why was not so pronounced experiments reported 15 years ago showing low-amplitude oscillations detected 170 K [Ch. W\"ursch et al.,...

Oscillations of magnetocrystalline anisotropy with the Pd overlayer thickness are found for (001) fcc $\mathrm{Pd}(p)/\mathrm{Co}(q)/\mathrm{Pd}(p)$ slabs within a realistic tight-binding model spin-orbit coupling treated as perturbation. The oscillations examined in simplified semianalytical and attributed to periodical appearance pairs majority-spin quantum-well states minority-spin resonances at Fermi level.

The oscillations of magnetocrystalline anisotropy (MA) energy with the increasing thickness a Pd overlayer in Co/Pd systems, obtained within realistic five-d-band tight-binding model, are analysed thoroughly order to determine uniquely basic origin oscillations. Several techniques applied achieve this goal, including real- and k-space breakdowns MA energy. shown, direct way, come from pairs majority-spin quantum-well states, confined overlayer, corresponding minority-spin resonances, both...

We derive, to leading order, the momentum-space functionals of exchange energy and quantum corrections electrostatic energy. The thus refined are used introduce a Kohn-Sham scheme for self-consistent calculations. This is applied helium beryllium. results differ from those obtained in standard configuration space. total binding energies predicted by computation somewhat better than configuration-space method.

The uniaxial in-plane magnetic anisotropy (UIP-MA) constant is calculated for a single step on the (001) surface of fcc $\mathrm{Co}(N)$ films. calculations are done both an undecorated and decorated with one or more, up to seven, Cu wires. Our objective explain mechanisms by which decoration decreases UIP-MA constant, effect observed experimentally ultrathin Co films deposited vicinal surfaces can lead reorientation magnetization within film plane. Theoretical performed realistic...

Two particular subjects tackled in the recent paper by Schirmer and Dreuw (SD) [J. A. Dreuw, Phys. Rev. A 75, 022513 (2007)] are commented on us. By providing a convincing example, we answer positively question posed SD whether local operator can be reconstructed from knowledge of its particle-hole matrix elements (when number particle states exceeds one). In connection with problem utmost reduction density-functional theory (DFT) to solution one equation for density amplitude---the radical...

A fully quantum-mechanical calculation of the Gilbert damping constant $\ensuremath{\alpha}$ in magnetic trilayers is done by employing torque-correlation formula within a realistic tight-binding model. remarkable enhancement Co/${\mathrm{NM}}_{1}$/${\mathrm{NM}}_{2}$ obtained due to adding caps ${\mathrm{NM}}_{2}$=Pd, Pt, and it decays with thickness spacers ${\mathrm{NM}}_{1}$=Cu, Ag, Au agreement experiment. Nonlocal origin visualized its atomic layer contributions. It shown that...

An algorithm for determination of the exchange potential is constructed and tested. It represents a one-step procedure based on equations derived by Krieger, Li, Iafrate (KLI) [Phys. Rev. A 46, 5453 (1992)], implemented already as an iterative K\"ummel Perdew Lett. 90, 043004 (2003)]. Due to suitable transformation KLI equations, we can solve them avoiding iterations. Our applied closed-shell atoms, from Be up Kr, within DFT exchange-only approximation. Using pseudospectral techniques...

The evolution of the domain structure with thickness bcc Fe films deposited on Ag(116) vicinal surface is studied by spin-polarized low-energy electron microscopy. We show that a spin reorientation transition proceeds via two mechanisms: continuous rotation magnetization within vertical plane perpendicular to steps and discontinuous in-plane component magnetization, leading splitting domains. In contrast previously investigated systems stripe domains, we reveal in case ferromagnetic surface,...

It is found that for closed-l-shell atoms, the exact local exchange potential vx(r) calculated in exchange-only Kohn–Sham (KS) scheme of density functional theory (DFT) very well represented within region every atomic shell by each suitably shifted potentials obtained with nonlocal Fock operator individual Hartree–Fock (HF) orbitals belonging to this shell. This newly revealed property not related well-known steplike structure response part vx(r), but it results from specific relations...

Magnetization switching by voltage pulses, microwaves, and optical pulses can be largely facilitated canted orientation of magnetization. Here, the authors demonstrate that a magnetization with virtually any achieved for thin Fe films, grown on stepped surface. The state tuned varying film thickness, capping an Au overlayer, taking advantage magnetic anisotropy oscillations due to quantum well states. observed evolution tilted is accurately reproduced within phenomenological model explained...

We incorporate the Scott correction into momentum-space energy functional of Thomas-Fermi model and so improve description strongly bound electrons. The resulting differential equation is then discussed, we report numerical results for neutral mercury.