31 research outputs found
Strongly enhanced orbital moments and anisotropies of adatoms on the Ag(001) surface
We present ob initio calculations for orbital moments and anisotropy energies of 3d and 5d adatoms on the Ag(001) surface, based on density functional theory, including Brooks' orbital polarization (OP) term, and applying a fully relativistic Korringa-Kohn-Rostoker-Green's function method. In general, we find unusually large orbital moments and anisotropy energies, e.g., in the 3d series. 2.57 mu (B) and +74 meV for Co, and, in the 5d series, 1.78 mu (B) and +42 meV for Os. These magnetic properties are determined mainly by the OP and even exist without spin-orbit coupling
Evaluation of the optical conductivity tensor in terms of contour integrations
For the case of finite life-time broadening the standard Kubo-formula for the
optical conductivity tensor is rederived in terms of Green's functions by using
contour integrations, whereby finite temperatures are accounted for by using
the Fermi-Dirac distribution function. For zero life-time broadening, the
present formalism is related to expressions well-known in the literature.
Numerical aspects of how to calculate the corresponding contour integrals are
also outlined.Comment: 8 pages, Latex + 2 figure (Encapsulated Postscript
Core reconstruction in pseudopotential calculations
A new method is presented for obtaining all-electron results from a
pseudopotential calculation. This is achieved by carrying out a localised
calculation in the region of an atomic nucleus using the embedding potential
method of Inglesfield [J.Phys. C {\bf 14}, 3795 (1981)]. In this method the
core region is \emph{reconstructed}, and none of the simplifying approximations
(such as spherical symmetry of the charge density/potential or frozen core
electrons) that previous solutions to this problem have required are made. The
embedding method requires an accurate real space Green function, and an
analysis of the errors introduced in constructing this from a set of numerical
eigenstates is given. Results are presented for an all-electron reconstruction
of bulk aluminium, for both the charge density and the density of states.Comment: 14 pages, 5 figure
Magneto-optical properties of ultra-thin surface layer systems
A first-principle description of the
magneto-optical Kerr effect (MOKE)
of ultra-thin surface layer systems is presented, that
is based on the concept of non-local
layer-resolved optical conductivity and the
corresponding solution of the
Maxwell equations.
This powerful approach allowed a detailed investigation
of the system Au(001)/nFe/mAu that shows
pronounced quantum-confinement effects.
In particular insight into the spatial origin of
magneto-optical properties
was obtained and
the reliability of simplified approaches
could be checked that way
for this important prototype
surface layer system