Related papers: Optical transitions in broken gap heterostructures
Two-dimensional (2D) materials have recently been the focus of extensive research. By following a similar trend as graphene, other 2D materials including transition metal dichalcogenides (MX2) and metal mono-chalcogenides (MX) show great…
Semiconductor-superconductor hybrids are widely used for realising complex quantum phenomena such as topological superconductivity and spins coupled to Cooper pairs. Accessing exotic regimes at high magnetic fields and increasing operating…
Dilute nitride bismide GaNBiAs is a potential semiconductor alloy for near- and mid-infrared applications, particularly in 1.55 $\mu$m optical communication systems. Incorporating dilute amounts of Bismuth (Bi) into GaAs reduces the…
An experimental study of optical phonon modes, both normal and interface (IF) phonons, in bilayer strain-coupled InAs/GaAs_(1-x)Sb_x quantum dot heterostructures has been presented by means of low-temperature polarized Raman scattering. The…
We present far-infrared magnetospectroscopy measurements of a HgTe quantum well in the inverted band structure regime over the temperature range of 2 to 60 K. The particularly low electron concentration enables us to probe the temperature…
Modern bandgap engineered electronic devices are typically made of multi-semiconductor multi-layer heterostructures that pose a major challenge to silicon-era characterization methods. As a result, contemporary bandgap engineering relies…
We present a theoretical model of split-gate quantum wires that are fabricated from GaAs-AlGaAs heterostructures. The model is built on the physical properties of donors and of semiconductor surfaces, and considerations of equilibrium in…
Hydrogen incorporation in diluted nitride semiconductors dramatically modifies the electronic and structural properties of the crystal through the creation of nitrogen-hydrogen complexes. We report a convergent beam electron-diffraction…
In$_2$Se$_3$ is a semiconductor material that can be stabilized in different crystal structures (at least one 3D and several 2D layered structures have been reported) with diverse electrical and optical properties. This feature has plagued…
We report real-space evidence for an in-plane vortex lattice (VL) transition in the multiband superconductor 2H-NbSe2, observed by laterally imaging subsurface vortices with scanning tunneling spectroscopy. With magnetic field applied ||…
The incorporation of bismuth (Bi) in GaAs results in a large reduction of the band gap energy (E$_g$) accompanied with a large increase in the spin-orbit splitting energy ($\bigtriangleup_{SO}$), leading to the condition that…
Electronic band structure and optical properties of zinc monochalcogenides with zinc-blende- and wurtzite-type structures were studied using the ab initio density functional method within the LDA, GGA, and LDA+U approaches. Calculations of…
We use tunable laser based Angle Resolved Photoemission Spectroscopy to study the electronic structure of the multi-band superconductor, MgB2. These results form the base line for detailed studies of superconductivity in multi-band systems.…
This paper presents a numerical implementation of a first-principles envelope-function theory derived recently by the author [B. A. Foreman, Phys. Rev. B 72, 165345 (2005)]. The examples studied deal with the valence subband structure of…
Studying the influence of breaking time-reversal symmetry on topological insulator surface states is an important problem of current interest in condensed matter physics and could provide a route toward proof-of-concept spintronic devices…
Transition metal monochalcogenides comprise a class of two-dimensional materials with electronic band gaps that are highly sensitive to material thickness and chemical composition. Here, we explore the tunability of the electronic…
High-resolution mapping of electronic properties at oxide heterointerfaces remains challenging due to probe delocalization and overlapping signals. In this work, we employ monochromated, probe-corrected scanning transmission electron…
Electron spin polarization up to 100% has been observed in type-II narrow-gap heterostructures with ultrathin InSb insertions in an InAs matrix via investigation of circularly polarized photoluminescence in an external magnetic field…
The interlayer exchange coupling mediated by valence band electrons in all-semiconductor IV-VI magnetic/nonmagnetic superlattices is studied theoretically. A 3D tight-binding model, accounting for the band and magnetic structure of the…
We performed ab initio simulations aimed at identifying the atomistic and electronic structure origin of the high valence and conduction band, and band gap tunability of halide perovskites. We found that the two key ingredients are the…