Magnetospectroscopy of double HgTe/CdHgTe QWs with inverted band structure in high magnetic fields up to 30 T

Magnetoabsorption in far and mid IR ranges in double HgTe/CdHgTe quantum wells with inverted band structure has been studied in high magnetic fields up to 30 T. Numerous intraband and interband transitions have been revealed in the spectra and interpreted within axial 8 × 8 k·p model. Splitting of dominant magnetoabsorption lines resulting from optical transitions from hole-like zero-mode Landau level has been discovered and discussed in terms of a built-in electric field and collective phenomena.     

Terahertz Spectroscopy of Two-Dimensional Semimetal in Three-Layer InAs/GaSb/InAs Quantum Well

JETP Letters - The features of terahertz photoluminescence and magnetoabsorption in magnetic fields up to 16 T in threelayer InAs/GaSb/InAs quantum wells with a band structure corresponding to a...     

Features of Photoluminescence of Double Acceptors in HgTe/CdHgTe Heterostructures with Quantum Wells in a Terahertz Range

JETP Letters - The terahertz photoluminescence spectra of HgTe/CdHgTe heterostructure with quantum wells under interband optical excitation with a power of 3 to 300 mW have been studied in the...     

Effects of the Electron—Electron Interaction in the Magneto-Absorption Spectra of HgTe/CdHgTe Quantum Wells with an Inverted Band Structure

JETP Letters - Magneto-absorption in HgTe/CdHgTe quantum wells with an inverted band structure in magnetic fields up to 30 T has been studied. It has been shown that the positions of...     

Origin of Structure Inversion Asymmetry in Double HgTe Quantum Wells

JETP Letters - The density dependences of the splitting values of the dominant magneto-absorption lines in undoped p-type double HgTe/CdHgTe quantum wells are studied. An analysis of the splitting...     

Field effect transistors for terahertz detection - silicon versus III–V material issue

Resonant frequencies of the two-dimensional plasma in FETs reach the THz range for nanometer transistor channels. Non-linear properties of the electron plasma are responsible for detection of THz radiation with FETs. Resonant excitation of plasma waves with sub-THz and THz radiation was demonstrated for short gate transistors at cryogenic temperatures. At room temperature, plasma oscillations are usually over-damped, but the FETs can still operate as efficient broadband THz detectors. The paper presents the main theoretical and experimental results on detection with FETs stressing their possible THz imaging applications. We discuss advantages and disadvantages of application of III–V GaAs and GaN HEMTs and silicon MOSFETs.     

Magnetoabsorption of Dirac Fermions in InAs/GaSb/InAs “Three-Layer” Gapless Quantum Wells

Subablative exposure of tightly focused visible-range femtosecond laser pulses on a thin translucent nanocrystalline copper(I) oxide on a silica glass substrate results not only in its annealing (resolidification), but apparently also in reduction of copper ions to the metallic state via single-photon absorption and the following thermal decomposition (disproportioning). Partial or complete ablation of the film within the laser focal spot and also its subablative optically contrast modification through formation of colloidal nanoparticles or annealing (resolidification) make it possible to consider this material in the thin-film form as a novel optical platform for direct laser writing of vis-IR metasurfaces and thin-film sensing plasmonic and all-dielectric nanostructures.