794 research outputs found
Optical and electronic properties of low-density InAs/InP quantum dot-like structures devoted to single-photon emitters at telecom wavelengths
Due to their band-structure and optical properties, InAs/InP quantum dots
(QDs) constitute a promising system for single-photon generation at third
telecom window of silica fibers and for applications in quantum communication
networks. However, obtaining the necessary low in-plane density of emitters
remains a challenge. Such structures are also still less explored than their
InAs/GaAs counterparts regarding optical properties of confined carriers. Here,
we report on the growth via metal-organic vapor phase epitaxy and investigation
of low-density InAs/InP QD-like structures, emitting in the range of 1.2-1.7
m, which includes the S, C, and L bands of the third optical window. We
observe multiple photoluminescence (PL) peaks originating from flat QDs with
height of small integer numbers of material monolayers. Temperature-dependent
PL reveals redistribution of carriers between families of QDs. Via
time-resolved PL, we obtain radiative lifetimes nearly independent of emission
energy in contrast to previous reports on InAs/InP QDs, which we attribute to
strongly height-dependent electron-hole correlations. Additionally, we observe
neutral and charged exciton emission from spatially isolated emitters. Using
the 8-band kp model and configuration-interaction method, we
successfully reproduce energies of emission lines, the dispersion of exciton
lifetimes, carrier activation energies, as well as the biexciton binding
energy, which allows for a detailed and comprehensive analysis of the
underlying physics.Comment: 13 pages, 9 figure
Thermobaric synthesis, structure, and properties of Dy x Cu 3V4O12
The perovskite-like compound Dy x Cu3V 4O12 (x = 0.67-0.75) is synthesized under high pressure (P = 4.0-9.0 GPa) and temperature (T = 1000 C). Its crystal structure is determined (Im-3 space group, Z = 2, a = 7.29348(7) Å) by means of powder X-ray diffraction. The basic lengths and bond angles are defined. It is found that the high-pressure phase of Dy x Cu3V 4O12 is characterized by metallic conductivity and paramagnetic properties. © 2013 Allerton Press, Inc
Investigation of interaction femtosecond laser pulses with skin and eyes mathematical model
We present a mathematical model of linear and nonlinear processes that takes place under the action of femtosecond laser radiation on the cutaneous covering. The study is carried out and the analytical solution of the set of equations describing the dynamics of the electron and atomic subsystems and investigated the processes of linear and nonlinear interaction of femtosecond laser pulses in the vitreous of the human eye, revealed the dependence of the pulse duration on the retina of the duration of the input pulse and found the value of the radiation power density, in which there is a self-focusing is obtained. The results of the work can be used to determine the maximum acceptable energy, generated by femtosecond laser systems, and to develop Russian laser safety standards for femtosecond laser systems
Optimization of Nanostructuring Burnishing Technological Parameters by Taguchi Method
On the basis of application of Taguchi optimization method, an approach for researching influence of nanostructuring burnishing technological parameters, considering the surface layer microhardness criterion, is developed. Optimal values of burnishing force, feed and number of tool passes for hardened steel AISI 420 hardening treatment are defined
Tensor analyzing power Ayy in deuteron inclusive breakup at large Pt and spin structure of deuteron at short internucleonic distances
The Ayy data for deuteron inclusive breakup off hydrogen and carbon at a
deuteron momentum of 9.0 GeV/c and large Pt of emitted protons are presented.
The large values of Ayy independent of the target mass reflect the sensitivity
of the data to the deuteron spin structure. The data obtained at fixed and
plotted versus Pt clearly demonstrate the dependence of the deuteron spin
structure at short internucleonic distances on two variables. The data are
compared with the calculations using Paris, CD-Bonn and Karmanov's deuteron
wave functions.Comment: 4 pages, 2 figures, talk given at the SPIN2004 Conf., 10-16 Oct.
2004, Triest, Ital
Two ideals connected with strong right upper porosity at a point
Let be the set of upper strongly porous at subsets of and let be the intersection of maximal ideals . Some characteristic properties of sets are obtained. It
is shown that the ideal generated by the so-called completely strongly porous
at subsets of is a proper subideal of Comment: 18 page
Tensor Ayy and vector Ay analyzing powers in the H(d,d')X and ^{12}C(d,d')X reactons at initial deuteron momenta of 9 GeV/c in the region of baryonic resonances excitation
The angular dependence of the tensor Ayy and vector Ay analyzing powers in
the inelastic scattering of deuterons with a momentum of 9.0 GeV/c on hydrogen
and carbon have been measured. The range of measurements corresponds to the
baryonic resonance excitation with masses 2.2--2.6 GeV/c^2. The Ayy data being
in good agreement with the previous results demonstrate an approximate
scaling up to -1.5 (GeV/c)^2. The large values of A_y show a significant role
of the spin-dependent part of the elementary amplitude of the NN->NN* reaction.
The results of the experiment are compared with model predictions of the
plane-wave impulse approximation.Comment: 7 pages, 7 figures. submitted to Yad.Fi
Architectural and Spiritual Monuments of the City in the Fate of Human
The article presents the biography of the architect and restorer, Anatoly Andreyevich Kuzmin, who devoted his whole life to preserving the spiritual heritage of the city of Nizhny Tagil – temple buildings. The story is told by the artist's granddaughter.В статье представлена биография архитектора и реставратора Анатолия Андреевича Кузьмина, посвятившего всю жизнь сохранению духовного наследия города Нижнего Тагила – храмовым постройкам. История рассказана внучкой художника
Optimization of Nanostructuring Burnishing Technological Parameters by Taguchi Method
On the basis of application of Taguchi optimization method, an approach for researching influence of nanostructuring burnishing technological parameters, considering the surface layer microhardness criterion, is developed. Optimal values of burnishing force, feed and number of tool passes for hardened steel AISI 420 hardening treatment are defined
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