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Optically Pumped Terahertz Radiation Sources Based on Impurity Carrier Transitions in Quantum Wells
Ch. 2. P. 21–38.
A review of the results of studies of terahertz radiation associated with impurity electron transitions in n-doped GaAs/AlGaAs quantum wells under conditions of interband optical excitation of nonequilibrium charge carriers is presented.The principles of radiation generation and methods of controlling its intensity are described: a decrease in the lifetime of electrons at impurity levels due to stimulated interband radiation and the introduction of a compensating acceptor impurity.
Melnikov A., Sokolik A. A., Selivanov Y. G. et al., Journal of Applied Physics 2025 Vol. 137 Article 163104
We report the observation of the electro-optic effect in Bi Se crystals induced by an intense single-cycle terahertz pulse. The effect reveals itself as a transient change of the polarization state of a femtosecond laser pulse reflected from the crystal that is exposed to the terahertz electric field. The corresponding experimental signal follows the field with a ...
Added: February 27, 2026
Vyacheslav D. Neverov, Karabassov T., Andrey V. Krasavin et al., Research 2026 Vol. 9 Article 1087
Majorana zero modes (MZMs) localized in vortex cores of topological superconductors are widely regarded promising building blocks for fault-tolerant quantum computation. However, their unambiguous detection is hindered by the extremely small energy spacing separating them from conventional Caroli-de Gennes-Matricon states. Using a microscopic Bogoliubov-de Gennes approach, we demonstrate that nonmagnetic impurities, rather than suppressing, can ...
Added: February 17, 2026
A. N. Lyubchak, K. V. Shein, G.N. Goltsman et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2024 Vol. 17 No. 3.2 P. 116–120
Terahertz (THz) integrated circuits is a promising platform to create low cost and efficient components for high-speed sixth-generation (6G) communication networks. One of the key components for this application is detectors and mixers integrated on THz silicon waveguide. Graphene, due to its unique and tunable properties such as zero band gap, high charge mobility and low electronic heat capacity, has ...
Added: November 5, 2024
Kravtsov M., Shilov A. L., Yang Y. et al., Nature Nanotechnology 2025 Vol. 20 No. 1 P. 51–56
Light incident upon materials can induce changes in their electrical conductivity, a phenomenon referred to as photoresistance. In semiconductors, the photoresistance is negative, as light-induced promotion of electrons across the bandgap enhances the number of charge carriers participating in transport. In superconductors and normal metals, the photoresistance is positive because of the destruction of the ...
Added: October 9, 2024
Adamov R. B., Melentev G. A., Podoskin A. A. et al., St. Petersburg Polytechnical University Journal: Physics and Mathematics 2024 Vol. 17 No. 1.1 P. 68–76
Comprehensive studies of the luminescence of p–i–n structures with 10 compensated GaAs/AlGaAs quantum wells have been performed. The studies were carried out in the terahertz (THz) and near-infrared (NIR) spectral ranges with both optical and electrical pumping of nonequilibrium charge carriers. The THz photoluminescence spectra revealed an emission line caused by electron transitions from the first size-quantization ...
Added: August 27, 2024
Svaytodukh S. S., Селиверстов С. В., Applied Physics Letters 2023 Vol. 124 No. 12
Added: May 12, 2024
Адамов Р. Б., Мелентьев Г. А., Подоскин А. А. et al., Физика и техника полупроводников 2023 Т. 57 № 8 С. 663–673
Исследованы фото- и электролюминесценция в p-i-n-структурах с компенсированными квантовыми ямами GaAs/AlGaAs с различными профилями легирования: с пространственным разделением доноров и акцепторов (доноры локализованы в квантовых ямах, акцепторы - в барьерах) и без него (и доноры, и акцепторы локализованы в квантовых ямах). Изучались спектральные характеристики люминесценции в ближнем ИК диапазоне при гелиевых температурах. Выявлены линии излучательной ...
Added: February 5, 2024
Blank T. G., Grishunin K. A., K. A. Zvezdin et al., Physical Review Letters 2023 Vol. 131 No. 2 Article 026902
The interaction of a single-cycle terahertz electric field with the topological insulator MnBi2Te4 triggers strongly anharmonic lattice dynamics, promoting fully coherent energy transfer between the otherwise noninteracting Raman-active Eg and infrared (IR)-active Eu phononic modes. Two-dimensional terahertz spectroscopy combined with modeling based on the classical equations of motion and symmetry analysis reveals the multistage process underlying the excitation of the ...
Added: January 14, 2024
Adamov R. B., Melentev G. A., Sedova I. V. et al., Journal of Luminescence 2024 Vol. 266 Article 120302
Terahertz (THz) luminescence in doped nanostructures with GaAs/AlGaAs quantum wells is studied under conditions of interband optical pumping. The study is carried out on compensated quantum wells with different doping profiles. In one structure, compensation is carried out directly in each quantum well by introducing donors and acceptors with the same concentration. In the other, ...
Added: November 12, 2023
Адамов Р. Б., Петрук А. Д., Мелентьев Г. А. et al., Научно-технические ведомости Санкт-Петербургского государственного политехнического университета. Физико-математические науки 2022 Т. 15 № 4 С. 32–43
In the paper, comparative studies of near-IR photoluminescence (PL) in structures with GaAs/AlGaAs quantum wells possessing different selective doping profiles have been performed. The PL spectra recorded at 5 K for different intensities of interband optical pumping were analyzed and main channels of radiative recombination were determined. The dependences of the main PL line intensities ...
Added: July 3, 2023
Nikolaev I., Kazakov A., Drozdov K. et al., Journal of Applied Physics 2022 Vol. 132 No. 23 Article 234301
We report a detailed study of the bipolar persistent photoconductivity in an HgTe/CdHgTe double quantum well (DQW), which can be a perspective for studying topological states in these structures. Photoconductivity spectra measurements in the range of 1.1–3.1 eV as well as transport measurements under different illumination conditions were performed at T = 4.2 K. Based on the results, the processes ...
Added: June 7, 2023
Новиков И. И., Няпшаев И. А., Гладышев А. Г. et al., Физика и техника полупроводников 2022 Т. 56 № 9 С. 933–939
Исследовано влияние состава волновода InGaAlAs на фотолюминесценцию и электролюминесценцию гетероструктур спектрального диапазона 1550 нм на основе тонких напряженных квантовых ям In0.74Ga0.26As. Предложен подход, позволяющий на основе анализа электролюминесценции провести сравнительный анализ параметров усиления изготовленных лазерных гетероструктур. Показано, что уменьшение доли алюминия в составе волноводных слоев гетероструктуры, согласованных по постоянной решетки с фосфидом индия, приводит к ...
Added: January 4, 2023