Related papers: Lifshitz tails for the Interband Light Absorption …
We have theoretically investigated nonlinear free-carrier absorption of terahertz radiation in InAs/AlSb heterojunctions. By considering multiple photon process and conduction-valence interband impact ionization (II), we have determined the…
We theoretically study the effect of THz radiation on the linear optical absorption spectra of semiconductor structures. A general theoretical framework, based on non-equilibrium Green functions, is formulated, and applied to the…
Urbach tails in semiconductors are often associated to effects of compositional disorder. The Urbach tail observed in InGaN alloy quantum wells of solar cells and LEDs by biased photocurrent spectroscopy is shown to be characteristic of the…
We present extensive metal-line absorption properties for 45 absorption systems that were selected by their Mg II absorption at redshifts between 0.4 and 1.4. For each system the properties of several chemical species are determined,…
In the present note, we determine the ground state energy and study the existence of Lifshitz tails near this energy for some non monotonous alloy type models. Here, non monotonous means that the single site potential coming into the alloy…
Van der Waals heterostructures obtained by artificially stacking two-dimensional crystals represent the frontier of material engineering, demonstrating properties superior to those of the starting materials. Fine control of the interlayer…
We combine predictions for several hierarchical cosmogonies with observational evidence on damped Lyman alpha systems to establish a correspondence between the high redshift galaxy population and the properties of damped Lyman alpha…
The absorption spectrum of CO$_2$ in the wavelength range 120\,nm --- 160\,nm is analyzed by means of quantum mechanical calculations performed using vibronically coupled PESs of five singlet valence electronic states and the coordinate…
We study the photoabsorption cross section and Fermi-edge singularities (FES) in graphene. For fillings below one half, we find, besides the expected FES in form of a peaked edge at the threshold (Fermi) energy, a second singularity to…
his study investigates the modifications of the thermal spectrum, at low frequency, induced by an external damping on a system in heat contact with internal fluctuating impurities. Those impurities can move among locations and their…
The frequency-dependent conductivity is studied for the one-dimensional Hubbard model, using a selection rule, the Bethe ansatz, and symmetries associated with conservation laws. For densities where the system is metallic the absorption…
It is suggested that a significant fraction of the low column-density absorption features seen in the spectra of quasars are produced in pressure-confined tidal debris, that was built up in small groups and clusters of galaxies over a…
The absorption lines observed in quasar spectra have given us a detailed picture of the intergalactic medium and the metal abundance and kinematics of high redshift galaxies. In this review, we present an introduction to the field, starting…
We present a model for a class of random binary lattices by introducing a one-dimensional system where impurities are placed in one sublattice while host atoms lie on the other sublattice. The source of disorder is the stochastic…
We study the electron states of a chain of non-identical, vertically stacked quantum dots (QDs). We discuss how the pseudo-band formed of the ground states confined in the QDs disintegrates upon increasing the inhomogeneity of the electron…
We report the discovery of a further line of sight allowing detection of HeII Ly alpha absorption by the intergalactic medium. A HST/STIS survey of 32 bright z ~ 3 quasars selected from the Hamburg Quasar Surveys yielded one detection…
We establish the Lifschitz-type singularity around the bottom of the spectrum for the integrated density of states for a class of subordinate Brownian motions in presence of the nonnegative Poissonian random potentials, possibly of infinite…
Electromagnetic characteristics of single-walled finite-length carbon nanotubes - absorption cross-section and field enhancement in the near zone - are theoretically studied in a wide frequency range from terahertz to visible. The analysis…
The light scattered by a cold trapped ion, which is in the stationary state of laser cooling, presents features due to the mechanical effects of atom-photon interaction. These features appear as additional peaks (sidebands) in the spectrum…
On the Lifshitz black brane geometry of an Einstein-Maxwell-dilaton gravity, we holographically investigate electric DC conductivities and the role of impurity in a non-relativistic Lifshitz medium with two different charge carriers,…