Related papers: Ellipsometric study of the Electronic Structure of…

The contribution of the fundamental gap E_ as well as those of the E_ + Delta(so) and E+ transitions to the dielectric function of GaAs1-xNx alloys near the band edge were determined from variable-angle spectroscopic ellipsometry and…

The electronic band structure of the (Ga,Mn)As system has been one of the most intriguing problems in solid state physics over the past two decades. Determination of the band structure evolution with increasing Mn concentration is a key…

Modulation photoreflectance spectroscopy and Raman spectroscopy have been applied to study the electronic- and band-structure evolution in (Ga,Mn)As epitaxial layers with increasing Mn doping in the range of low Mn content, up to 1.2%.…

Structural and optical properties of MBE-grown GaAs(001) surface have been studied by reflection high-energy electron diffraction and single-wavelength ellipsometry under dynamic conditions of ramp heating after desorption of passivating…

Imaging ellipsometry studies of graphene on SiO2/Si and crystalline GaAs are presented. We demonstrate that imaging ellipsometry is a powerful tool to detect and characterize graphene on any flat substrate. Variable angle spectroscopic…

Ultrafast two-color pump-probe measurements, involving coherent acoustic phonon (CAP) waves, have provided information simultaneously on the mechanical properties and on the electronic structure of ferromagnetic GaMnAs. The elastic constant…

The diluted (Ga,Mn)As became a model ferromagnetic semiconductor, however there is still a disagreement on the source of its magnetism. The divergences arise from the results indicating that the holes mediated ferromagnetism reside in the…

Spectroscopic ellipsometry is used to determine the dielectric function of the superconducting LaFeAsO$_{0.9}$F$_{0.1}$ ($T_c$ = 27 K) and undoped LaFeAsO polycrystalline samples in the wide range 0.01-6.5 eV at temperatures 10 $\leq T…

Fundamental optical properties of thin films of (Ga,Mn)As diluted ferromagnetic semiconductor with a low (1%) and high (6%) Mn content and of a reference GaAs film, grown by low-temperature molecular-beam epitaxy, have been investigated by…

The electronic structure and chemical bonding of wurtzite-GaN investigated by N 1s soft x-ray absorption spectroscopy and N K, Ga M1, and Ga M2,3 emission spectroscopy is compared to that of pure Ga. The measurements are interpreted by…

We study the optical conductivity in the III-V diluted magnetic semiconductor GaMnAs and compare our calculations to available experimental data. Our model study is able to reproduce both qualitatively and quantitatively the observed…

We demonstrate that optical transparency of any two-dimensional system with a symmetric electronic spectrum is governed by the fine structure constant and suggest a simple formula that relates a quasi-particle spectrum to an optical…

After two decades from the discovery of ferromagnetism in Mn-doped GaAs, its origin is still debated, and many doubts are related to the electronic structure. Here we report an experimental and theoretical study of the valence electron…

We report on a systematic study of optical properties of (Ga,Mn)As epilayers spanning the wide range of accessible substitutional Mn_Ga dopings. The growth and post-growth annealing procedures were optimized for each nominal Mn doping in…

We demonstrate electrochemical top gating of graphene by using a solid polymer electrolyte. This allows to reach much higher electron and hole doping than standard back gating. In-situ Raman measurements monitor the doping. The G peak…

Preliminary results based on a large compilation of line-strength profiles are presented and discussed. Elliptical galaxies (Es) with strong central Mg$_2$ show steeper line-strength gradients. These galaxies are more massive and have…

The ability to directly observe electronic band structure in modern nanoscale field-effect devices could transform understanding of their physics and function. One could, for example, visualize local changes in the electrical and chemical…

The spin state of holes bound to Mn acceptors in GaMnAs is investigated by optical spectroscopy. Concentrations of Mn from 10^17 to 10^19 cm^-3 were studied as a function of magnetic field and temperature. The photoluminescence from…

We have investigated the electronic structure of the dilute magnetic semiconductor (DMS) $Ga_{0.98}Mn_{0.02}P$ and compared it to that of an undoped $GaP$ reference sample, using hard X-ray photoelectron spectroscopy (HXPS) and hard X-ray…

Lattice matched GaAs/AlGaAs epitaxial structures with quantum dots are studied under static uniaxial stress applied either along the $[001]$ or $[110]$ crystal directions. We conduct simultaneous measurements of the spectral shifts in the…