144 research outputs found
Origin of Magnetic Circular Dichroism in GaMnAs: Giant Zeeman Splitting versus Spin Dependent Density of States
We present a unified interpretation of experimentally observed magnetic
circular dichroism (MCD) in the ferromagnetic semiconductor (Ga,Mn)As, based on
theoretical arguments, which demonstrates that MCD in this material arises
primarily from a difference in the density of spin-up and spin-down states in
the valence band brought about by the presence of the Mn impurity band, rather
than being primarily due to the Zeeman splitting of electronic states.Comment: 4+ pages, 4 figure
Observation of surface states on heavily indium doped SnTe(111), a superconducting topological crystalline insulator
The topological crystalline insulator tin telluride is known to host
superconductivity when doped with indium (SnInTe), and for low
indium contents () it is known that the topological surface states are
preserved. Here we present the growth, characterization and angle resolved
photoemission spectroscopy analysis of samples with much heavier In doping (up
to ), a regime where the superconducting temperature is increased
nearly fourfold. We demonstrate that despite strong p-type doping, Dirac-like
surface states persist
Effect of rapid thermal annealing on short period {CdO/ZnO}m SLs grown on m-Al2O3
Here, we report on the characterization of {CdO/ZnO}m superlattice structures
(SLs) grown by plasma assisted molecular beam epitaxy. The properties of
as-grown and annealed SLs deposited on m-oriented sapphire were investigated by
secondary ion mass spectrometry (SIMS) and scanning electron microscopy (SEM)
in cathodoluminescence (CL) and energy dispersive X-ray modes. The deformation
of the crystallographic structure of SLs was observed after rapid thermal
annealing at 900{\deg}C in oxygen flow due to migration and segregation of Cd
atoms. SIMS measurements revealed that the distributions of cadmium in the
annealed samples depend on the thicknesses of the CdO and ZnO sublayers in the
as grown superlattice structures. Depth-resolved CL measurements showed that
shifting of the near band edge emission peaks is closely related to the Cd
profiles measured with SIMS.Comment: 14 pages, 6 figure
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