22 research outputs found
Comment on "Spin and spin current -- From fundamentals to recent progress", by Sadamichi Maekawa et al, arXiv: 2211.02241v3
Important omissions in arXiv:2211.02241v3, "Spin and spin current -- From
fundamentals to recent progress", by Sadamichi Maekawa et al, are indicated.Comment: 1 pag
Spin-density induced by electromagnetic wave in two-dimensional electron gas with both Rashba and Dresselhaus spin-orbit couplings
We consider the magnetic response of a two-dimensional electron gas (2DEG)
with both Rashba and Dresselhaus spin-orbit coupling to a microwave excitation.
We generalize the results of [A. Shnirman and I. Martin, Europhys. Lett. 78,
27001 (2007).], where pure Rashba coupling was studied. We observe that the
microwave with the in-plane electric field and the out-of-plane magnetic field
creates an out-of-plane spin polarization. The effect is more prominent in
clean systems with resolved spin-orbit-split subbands. Considered as response
to the microwave magnetic field, the spin-orbit contribution to the
magnetization far exceeds the usual Zeeman contribution in the clean limit. The
effect vanishes when the Rashba and the Dresselhaus couplings have equal
strength.Comment: 4 pages, 2 figure
Quantum and Thermal Depinning of a String from a Linear Defect
The problem of a massive elastic string depinning from a linear defect under
the action of a small driving force is considered. To exponential accuracy the
decay rate is calculated with the help of the instanton method; then,
fluctuations of the quasiclassical solution are taken into account to determine
the preexponential factor. The decay rate exhibits a kind of first order
transition from quantum tunneling to thermal activation with vanishing
crossover region. The model may be applied to describe nucleation in
2-dimensional first order quantum phase transitions.Comment: Revtex. 11 pages + 4 PS figures. Accepted for publication in PR
Field Effect Transistors for Terahertz Detection: Physics and First Imaging Applications
Resonant frequencies of the two-dimensional plasma in FETs increase with the
reduction of the channel dimensions and can reach the THz range for sub-micron
gate lengths. Nonlinear properties of the electron plasma in the transistor
channel can be used for the detection and mixing of THz frequencies. At
cryogenic temperatures resonant and gate voltage tunable detection related to
plasma waves resonances, is observed. At room temperature, when plasma
oscillations are overdamped, the FET can operate as an efficient broadband THz
detector. We present the main theoretical and experimental results on THz
detection by FETs in the context of their possible application for THz imaging.Comment: 22 pages, 12 figures, review pape
Stationary and coherent spectroscopy of 167
We have conducted a spectroscopic investigation of 167Er3+ ions in optical waveguides on an optical transition between the hyperfine sublevels of 4I15/2 and 4I9/2 multiplets. Waveguides with diameters ranging from 20 to 100 µm were produced in the crystal by a femtosecond laser using the depressed-cladding approach. The spectroscopy results of 167Er3+ ions inside the waveguides show additional broadening and an overall shifts of the spectra compared to the bulk spectrum of ions. The sign of the observed frequency shift depends on the diameter of the specific waveguide. We have also observed a two-pulse photon echo in several waveguides. The acquired results show the possibility for integrated quantum schemes in rare-earth ions doped crystals
Surface Treatment of Carbon Fiber Reinforcement to Increase Adhesion with Butadiene Elastomer
В работе приводятся результаты исследования увеличения адгезионного
взаимодействия бутадиенового эластомера с армирующей тканью на основе углеволокна.
Повышения адгезии эластомера с углеволокном добивались путем поверхностной обработки
армирующей ткани, растворенной резиновой смесью в толуоле и клеем Хемосил. В результате
исследования высокомодульных материалов на расслоение эластомера от углеволокна
наблюдается повышение прочности адгезии. При обработке хемосилом армирующей ткани
разрушение происходит по эластомеру, прочность соединения с углеволокном превышает
когезионную прочность эластомера. Увеличение адгезии между армирующим наполнителем
и бутадиеновой матрицей приводит к изменению упругопрочностных свойств
полученных
высокомодульных материалов, происходит увеличение прочности при разрыве, твердости,
снижение относительного удлинения и абразивостойкости. Методом электронной микроскопии
установлено, что поверхностная обработка углеткани приводит к образованию плотного контакта
с эластомерной матрицей. При помощи термомеханического анализа показано, что данные
материалы могут эксплуатироваться при отрицательных температурахThis study presents the results of the study of increasing the adhesive interaction of butadiene elastomer with the reinforcing fabric based on carbon fiber. Increased adhesion of elastomer with carbon fiber was achieved by surface treatment of reinforcing fabric with dissolved rubber mixture in toluene and Chemosil adhesive mixture. Examination of high-modulus materials for delamination of elastomer from carbon fiber showed an increase in adhesion strength. When a reinforcing fabric is treated with Chemosil adhesive mixture, the destruction occurs over the elastomer, the bond strength to the carbon fiber exceeds the cohesive strength of the elastomer. Increase of adhesion between reinforcing filler and butadiene matrix leads to change of elastic and strength properties of obtained high-modulus materials: increase of tensile strength and hardness, decrease of relative elongation and abrasion resistance. The method of electron microscopy has established that the surface treatment of carbon fabric leads to the formation of a dense contact with the elastomeric matrix. Thermomechanical analysis shows that these materials can be operated at negative temperature
Spin physics in semiconductors
This book offers an extensive introduction to the extremely rich and intriguing field of spin-related phenomena in semiconductors. In this second edition, all chapters have been updated to include the latest experimental and theoretical research. Furthermore, it covers the entire field: bulk semiconductors, two-dimensional semiconductor structures, quantum dots, optical and electric effects, spin-related effects, electron-nuclei spin interactions, Spin Hall effect, spin torques, etc. Thanks to its self-contained style, the book is ideally suited for graduate students and researchers new to the field