535 research outputs found
Magneto-optical properties of Co|Pt multilayer systems
We are reporting, for the first time in the literature, theoretical Kerr
spectra of Co|Pt multilayer systems as obtained on a first principles basis
including multiple reflections and interferences from all the boundaries
in-between the layers.Comment: 4 pages (LaTeX), 1 (a,b) figures (Encapsulated PostScript), J. Appl.
Physics, in pres
Layer-resolved optical conductivity of Co|Pt multilayers
The complex optical conductivity tensor is calculated for the Co|Pt systems
by applying a contour integration technique within the framework of the
spin-polarized relativistic screened Korringa-Kohn-Rostoker method. It is shown
that the optical conductivity of the Co|Pt multilayer systems is dominated by
contributions arising from the Pt cap and/or substrate layers.Comment: 7 pages (LaTeX), 2 (a,b) figures (Encapsulated PostScript), J. Magn.
Magn. Materials, in pres
Orbital dependent electron tunneling within the atom superposition approach: Theory and application to W(110)
We introduce an orbital dependent electron tunneling model and implement it
within the atom superposition approach for simulating scanning tunneling
microscopy (STM) and spectroscopy (STS). Applying our method, we analyze the
convergence and the orbital contributions to the tunneling current and the
corrugation of constant current STM images above the W(110) surface. In
accordance with a previous study [Heinze et al., Phys. Rev. B 58, 16432
(1998)], we find atomic contrast reversal depending on the bias voltage.
Additionally, we analyze this effect depending on the tip-sample distance using
different tip models, and find two qualitatively different behaviors based on
the tip orbital composition. As an explanation, we highlight the role of the
real space shape of the orbitals involved in the tunneling. STM images
calculated by our model agree well with Tersoff-Hamann and Bardeen results. The
computational efficiency of our model is remarkable as the k-point samplings of
the surface and tip Brillouin zones do not affect the computation time, in
contrast to the Bardeen method.Comment: 28 pages manuscript, 7 figures, 1 tabl
Simulation of spin-polarized scanning tunneling microscopy on complex magnetic surfaces: Case of a Cr monolayer on Ag(111)
We propose an atom-superposition-based method for simulating spin-polarized
scanning tunneling microscopy (SP-STM) from first principles. Our approach
provides bias dependent STM images in high spatial resolution, with the
capability of using either constant current or constant height modes of STM. In
addition, topographic and magnetic contributions can clearly be distinguished,
which are directly comparable to results of SP-STM experiments in the
differential magnetic mode. Advantages of the proposed method are that it is
computationally cheap, it is easy to parallelize, and it can employ the results
of any ab initio electronic structure code. Its capabilities are illustrated
for the prototype frustrated hexagonal antiferromagnetic system, Cr monolayer
on Ag(111) in a noncollinear magnetic N\'eel state. We show
evidence that the magnetic contrast is sensitive to the tip electronic
structure, and this contrast can be reversed depending on the bias voltage.Comment: 28 pages manuscript, 1 table, 5 figure
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