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1.
New results are presented of an experimental investigation of the spectrum of 36P → 37P two-photon microwave transition in Rydberg atoms of sodium in a constant electric field. Depending on the conditions of excitation of the initial 36P state (the constant electric field is switched on either before or after the exciting laser pulse) and polarization of laser radiation, a strong variation is observed of the amplitudes of individual two-photon transitions between the fine-structure Stark components of the 36P and 37P states. This effect is an analog of the Paschen-Back effect in a strong magnetic field and is due to the break of L-S coupling and to the variation of the wave functions of Rydberg electrons in an electric field. It is also found that the break of L-S coupling affects considerably the shape of double Stark resonance arising upon intersection of the virtual intermediate level of two-photon transition with the real intermediate 37S level. 相似文献
2.
3.
The results of an investigation of the magnetocaloric effect in the CoTi-M and CoZn-W hexaferrite systems in the 150–500 K temperature range are presented. It is shown that the maxima of the magnetocaloric effect correspond to spontaneous spin-orientational transitions leading to transformation of the magnetic structure from easy-plane to uniaxial and to resultant changes in the values and signs of the magnetic anisotropy constant as a function of the composition and temperature. Estimates of the T(T) relation taking into account the magnetic anisotropy constants K1, K2, and K3, which are known for the compounds considered, agree well with experiment. Hence, the main contribution to the magnetocaloric effect at temperatures far from the Curie point in the materials in question is governed by the rotation of the magnetization vector.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 63–68, October, 1993. 相似文献
4.
5.
E. A. Yakshina D. B. Tretyakov V. M. Entin I. I. Beterov I. I. Ryabtsev 《Journal of Experimental and Theoretical Physics》2020,130(2):170-182
The dipole blockade effect at laser excitation of mesoscopic ensembles of Rydberg atoms lies in the fact that the excitation of one atom to a Rydberg state blocks the excitation of other atoms due to the shift in the collective energy levels of interacting Rydberg atoms. It is used to obtain the entangled qubit states based on single neutral atoms in optical traps. In this paper, we present our experimental results on the observation of the dipole blockade for mesoscopic ensembles of 1–5 atoms when they are detected by the selective field ionization method. We have investigated the spectra of the three-photon laser excitation 5S1/2 → 5P3/2 → 6S1/2 → nP3/2 of cold Rydberg Rb atoms in a magneto-optical trap. We have found that for mesoscopic ensembles this method allows only a partial dipole blockage to be observed. This is most likely related to the presence of parasitic electric fields reducing the interaction energy of Rydberg atoms, the decrease in the probability of detecting high states, and the strong angular dependence of the interaction energy of Rydberg atoms in a single interaction volume. 相似文献
6.
T. S. Goncharova S. G. Konnikov N. G. Ryabtsev D. N. Tret'yakov T. P. Aleksandrova 《Russian Physics Journal》1973,16(9):1322-1324
Conclusions Crystallization from a solution of antimony in a gallium-aluminum melt has been used to produce epitaxial AlxGa1–xSb films with x=0 to 0.4; isothermal (T = 450, 500, 550°C) and isoconcentration (0; 1; 2.4 at. % Al) sections have been drawn for the liquidus surface on the composition plane. X-ray microspectral analysis has been used to examine the composition of the AlxGa1–xSb films in relation to aluminum content in the melt, as well as the distribution of Al and Ga over the epitaxial film. These films had a perfect structure. The results enable one to determine the solution composition needed to grow AlxGa1–xSb epitaxial films at 450–550°C on gallium antimonide substrates, and it is shown to be possible to make heterostructures in the AlxGa1–xSb-GaSb system.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, Vol. 16, No. 9, pp. 146–148, September.We are indebted to Zh. I. Alferov and V. I. Shveikin for attention and support in this work. 相似文献
7.
The effect of microwave radiation on the resonance fluorescence of a cloud of cold 85Rb atoms in a magnetooptical trap is studied. The radiation frequency was tuned near the hyperfine splitting frequency of rubidium atoms in the 5S ground state. The microwave field induced magnetic dipole transitions between the magnetic sublevels of the 5S (F=2) and 5S (F=3) states, resulting in a change in the fluorescence signal. The resonance fluorescence spectra were recorded by tuning the microwave radiation frequency. The observed spectra were found to be substantially dependent on the transition under study and the frequency of a repump laser used in the cooling scheme. 相似文献
8.
A method to calculate the loss coefficient of amplified luminescence loss
lum in the active layer of a laser diode on the basis of radiation transfer equations and the balance between emission, amplification, and absorption of spontaneous radiation is suggested. The values of loss
lum and also of the density of fluxes of amplified luminescence have been determined in one- and two-dimensional approximations for laser diodes based on GaAs, GaN, and ZnSe compounds with different configurations of resonators. 相似文献
9.
Ishchenko A. A. Kurdyukova I. V. Bogdanovich M. V. Bondarev S. L. Romanenko A. A. Ryabtsev A. G. Ryabtsev G. I. 《Optics and Spectroscopy》2021,129(8):926-934
Optics and Spectroscopy - We found that the long-wavelength absorption band of the laser dye IR 1061 and its analogue with an unsubstituted polymethine chain is strongly broadened and decreases in... 相似文献
10.
V. V. Kabanov Y. V. Lebiadok A. A. Ramanenka A. G. Ryabtsev G. I. Ryabtsev A. S. Smal S. K. Mehta 《Journal of Applied Spectroscopy》2011,77(6):810-816
A system of radiative transfer equations is used to calculate the loss coefficient for amplified luminescence fluxes propagating
along and transverse to the cavity axis in the active layer of high-power laser diode arrays taking the spreading of charge
carriers in the cladding and contact layers of InGaAs/GaAs/AlGaAs heterostructures into account. It is shown that the spreading
of charge carriers leads to a significant change in the amplified luminescence flux which can contribute up to 18% to the
lasing threshold of these laser diode arrays. The calculated loss coefficients can greatly simplify the determination of the
amplified luminescence fluxes in laser diode arrays with an error of less that 16% and can be used to determine how much the
amplified luminescence affects the power and dynamic characteristics of diode arrays. 相似文献