Related papers: Valence band spectroscopy in V-grooved quantum wir…
The magnetic field dependence of photoabsorption provides direct insights into the band structure of semiconductors. It is perhaps surprising that there is a large discrepancy between electron, hole, and reduced mass reported in the recent…
A one-dimensional, two-channel quantum wire is studied in the effective non-Hermitian Hamiltonian framework. Analytical expressions are derived for the band structure of the isolated wire. Quantum states and transport properties of the wire…
We present an electronic structure calculation of the valence band for some II--VI binary/ternary alloy interfaces. We use the empirical tight-binding method and the surface Green's function matching method. For the ternary alloys we use…
We use a coherent fiber bundle to demonstrate the endoscopic absorption imaging of quantum gases. We show that the fiber bundle introduces spurious noise in the picture mainly due to the strong core-to-core coupling. By direct comparison…
We report on time-resolved and steady-state photoluminescence studies of GaAs/AlGaAs V-groove quantum wire structures. Steady-state photoluminescence experiments are performed in the temperature range from 8K to 200K. We evaluate the…
We present a method to measure the spectral density of in-band optical transmission impairments without coherent electrical reception and digital signal processing at the receiver. We determine the method's accuracy by numerical simulations…
We report measurements of the compressibility of a one-dimensional (1D) quantum wire, defined in the upper well of a GaAs/AlGaAs double quantum well heterostructure. A wire defined simultaneously in the lower well probes the ability of the…
Polarization dependent x-ray absorption spectroscopy was used to study the magnetic ground state and the orbital occupation in bulk-phase VI$_3$ van der Waals crystals below and above the ferromagnetic and structural transitions. X-ray…
The anisotropy in the electronic structure of the inherently nanolaminated ternary phase Cr$_{2}$GeC is investigated by bulk-sensitive and element selective soft x-ray absorption/emission spectroscopy. The angle-resolved absorption/emission…
We present a discussion of the admittance (ac-conductance) and nonlinear I-V-characteristic for a number of mesoscopic conductors. Our approach is based on a generalization of the scattering approach which now includes the effects of the…
Semiconductor coupled quantum dots provide a unique opportunity of tuning bandgaps by tailoring band offsets, making them ideal for photovoltaic and other applications. Here, we have studied stability, trends in the band gap, band offsets,…
Due to the diverging density of states (DOS), Van Hove singularities (VHS) near the Fermi level are known to boost the susceptibility to a wide variety of electronic instabilities, including superconductivity. We theoretically show that the…
By performing firt-principles electronic calculations we propose new a phase of group-V allotropes of antimonene, arsenene and phosphorene in the pentaoctite structure. By calculating the phonon spectra, we show that all these phases are…
Energy level structure and direct light absorption in a cylindrical quantum dot, having thin falciform cross section, are studied within the framework of the adiabatic approximation. An analytical expression for the energy spectrum of the…
We present the mathematical and numerical theory for evanescent waves in subwavelength band gap materials. We begin in the one-dimensional case, whereby fully explicit formulas for the complex band structure, in terms of the capacitance…
We study the spectral properties of one-dimensional quantum wire with a single defect. We reveal the existence of the non-trivial topological structures in the spectral space of the system, which are behind the exotic quantum phenomena that…
We consider the absorption of microwaves by a quantum Hall droplet. We show that the number and velocities of charged edge modes can be directly measured from a droplet of known shape. In contrast to standard transport measurements,…
Traditionally, spectroscopy is performed by examining the position of absorption lines. However, at frequencies near the transition frequency, additional information can be obtained from the phase shift. In this work we consider the…
We have investigated the electronic structure of LaFeAsO$_{1-x}$F$_{x}$ (x = 0; 0.1; 0.2) by angle-integrated photoemission spectroscopy and local density approximation (LDA) based band structure calculations. The valence band consists of a…
The improvement of light absorption in Si/BeSe$_{0.41}$Te$_{0.59}$ heterostructures for solar cell applications is studied theoretically. First, using simple approaches we found that light absorption could be improved in a single…