142 research outputs found

    Origin of Magnetic Circular Dichroism in GaMnAs: Giant Zeeman Splitting versus Spin Dependent Density of States

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    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

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    The topological crystalline insulator tin telluride is known to host superconductivity when doped with indium (Sn1−x_{1-x}Inx_{x}Te), and for low indium contents (x=0.04x=0.04) 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 x≈0.4x\approx0.4), 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

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    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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