The behaviour of the band-edge states is investigated for a lattice with a substitutional impurity and for the Tamm model of a semi-infinite crystal. Both relativistic and nonrelativistic treatments are considered. On this basis the paradox arising out of the existence of Dirac impurity states and...
Band-edge states and oscillator strengths in four configurations of ultrasmall Si quantum boxes (QBs) with (100) planes saturated by H have been calculated using the extended Hckel-type non-orthogonal tight-binding method. It is found that, while the valence-band edge states are always bulk ...
Strong spin-independent edge disorder, on the other hand, leads to the appearance of new weakly disordered midgap states in the layers adjacent to the disordered edge, i.e., at the interface between the bulk topological superconductor and the one-dimensional Anderson insulator formed by the ...
We present a tight-binding investigation of the electron and hole band-edge states for GaAs/AlAs heterostructures. Quantum wells are studied near the critical width in which the system undergoes a direct- to indirect-gap transition. Results are compared for first- and second-nearest-neighbor models...
Single band-edge states can trap light and function as high-quality optical feedback for microscale lasers and nanolasers. However, access to more than a single band-edge mode for nanolasing has not been possible because of limited cavity designs. Here,
we show that the highly directional intralayer and interlayer couplings, together with the unusual stereoelectronic effects of the Sn 5s lone pair in α-SnO, may be exploited to tune, in addition to the band gap, the valence and conduction band-edge states selectively using in-plane and/or ...
The parameterized band dispersions are explored, and the density-of-states (DOS) as well as the constant energy surfaces are calculated and analyzed. The carrier concentration and the Fermi energyEFin the intrinsic alloys as functions of the temperature is determined from the DOS. The carrier ...
Using first-principles calculations, here we propose a dopant ionization process for two-dimensional semiconductors where charge carriers are only excited to a set of defect-bound band edge states, rather than to the true band edge states, as is the case in three-dimensions. These defect-bound ...
However, two distinct band edge states below the conduction band, observed by spectroscopic ellipsometry measurement, undergo a thermal change as a function of annealing ambient atmosphere and these changes are correlated to changes in carrier concentration and mobility. (C) 2012 The Electrochemical ...
By analytically modeling the triplon dispersion, we show that BaCuSiOClis the first bosonic realization of the coupled Su-Schrieffer-Heeger model, where the presence of topologically protected edge states is prompted by a bipartite nature of the lattice....