卷 123, 编号 4 (2017)

In the one-configuration approximation, in the formalism of irreducible tensor operators, and in the intermediate (real) coupling scheme, numerical values of the fine-structure parameters are determined for the 3p4f and 3p5f highly excited configurations of the P II phosphorus ion with the energy-operator matrix in the LK-coupling approximation. With these values of the fine-structure parameters, the energy-operator matrix is numerically diagonalized in the LS-coupling approximation. The gyromagnetic ratios calculated in both basis sets in the absence of a field are compared with one another, as well as with their vector counterparts and the experimental g-factors available for the 3p4f configuration. The experimental and theoretical g-factors calculated with the LS basis set are in good agreement with the sole exception of the ³F₂ level. Note that the calculation of g-factors from the Zeeman splitting in the linear region totally confirmed their agreement with the values calculated in the LS basis set (g_LS) in the absence of a field. The gyromagnetic ratios are the main objectives of this and previous papers, especially for configurations for which experimental data are absent. Apart from the g-factors, the specific features of Zeeman splitting (the crossings and anticrossings of magnetic components) in the 3p5f configurations were determined. These data are to be compared with results of future experiments. Comparison of gyromagnetic ratios calculated in the intermediate coupling scheme with their vector counterparts showed that most levels of the configurations studied are closer than in the LK-coupling scheme.

The Stark shift of the CI 2479 Å emission line of atomic carbon is measured in a broad range of electron densities between ~6 × 10¹⁶ and ~4 × 10¹⁸ cm^–3. It is established that the shift is linear and its value is significantly lower than that predicted by theory. The line shape is found to be dominated by the Stark effect at Т = 32 kK and electron concentration N_e ≈ 3.9 × 10¹⁸ cm^–3. The electron-impact and ion widths of this contour are in good agreement with the Grim data, while its total shift to longer wavelengths is found to be half that calculated theoretically.

The photophysics and electronic structure of tribenzotetraazachlorins (H₂, Zn, and Mg), which are novel analogues of phtalocyanines, have been studied experimentally and theoretically. At 293 K, the electronic absorption, fluorescence, and fluorescence excitation spectra are recorded and the fluorescence quantum yield and lifetime, as well as the quantum yield of singlet oxygen generation, are measured; at 77 K, the fluorescence, fluorescence excitation, and fluorescence polarization spectra are recorded and the fluorescence lifetime values are measured. The dependences of the absorption spectra and photophysical parameters on the structure variation are analyzed in detail. Quantum-chemical calculations of the electronic structure and absorption spectra of tribenzotetraazachlorins (H₂, Mg) are performed using the INDO/Sm method (modified INDO/S method) based on molecular-geometry optimization by the DFT PBE/TZVP method. The results of quantum-chemical calculations of the electronic absorption spectra are in very good agreement with the experimental data for the transitions to two lower electronic states.

The spectral properties of singlet-oxygen luminescence at the ¹Δ_g → ³Σ_g transition observed using fullerene as a photosensitizer are analyzed. It is shown that the use of C₆₀ and C₇₀ fullerenes for singlet-oxygen generation exhibits all the main spectral regularities observed for other photosensitizers. The results of investigations in this field are summarized.

Photodesorption of rubidium atoms from crystalline sapphire surface is experimentally studied using the time-of-flight method and the total internal reflection effect. The adsorption energy of rubidium atoms on sapphire is determined to be ~0.7 eV. The dependence of the kinetic energy of desorbed rubidium atoms on the desorbing photon energy in the sapphire transparency range and in the absorption band of rubidium adatoms is determined. It is found that the average kinetic energy of outgoing atoms decreases at desorbing photon energies exceeding 2.3 eV. A model is proposed that relates the decrease in the kinetic energy of desorbed atoms to the appearance of a new channel of desorption of atoms in an excited electronic state.

We have developed a theory of the transient absorption of femtosecond light pulses by free electrons in the course of intraband transitions involving the participation of phonons. General expressions have been obtained for the probability of transition of an electron from the bottom of the conduction band to a highly excited state due to the absorption of several photons and either the absorption or emission of a phonon.

The processes of molecular relaxation in the solid NaNO₃–NaNO₂ and KNO₃–KNO₂ “nitrate–nitrite” binary systems have been investigated by Raman spectroscopy. The relaxation time of the vibration ν₁(A) of an NO^-₃ anion in the binary system is found to be shorter than that in individual nitrate. The increase in the relaxation rate is explained by the existence of an additional mechanism of relaxation of vibrationally excited states of the nitrate ion in the system. This mechanism is related to the excitation of vibration of another anion (NO^-₂) and generation of a lattice phonon. It has been established that this relaxation mechanism is implemented provided that the difference between the frequencies of the aforementioned vibrations correspond to the range of sufficiently high density of states in the phonon spectrum.

Spectral properties and luminescence under the photo- and electroexcitation of three new zinc and beryllium metal complexes with substituted triazole ligands are investigated. Spectral properties are reported for solutions of chloroform and for films obtained by thermovacuum deposition.

A quantum-memory unit scheme on the base of a semiconductor structure with quantum dots is proposed. The unit includes a microresonator with single and double quantum dots performing frequencyconverter and charge-qubit functions, respectively. The writing process is carried out in several stages and it is controlled by optical fields of the resonator and laser. It is shown that, to achieve high writing probability, it is necessary to use high-Q resonators and to be able to suppress relaxation processes in quantum dots.

Based on the scattering matrix formalism, we have developed a method of quantization of an electromagnetic field in two-dimensional photonic nanostructures (S-quantization in the two-dimensional case). In this method, the fields at the boundaries of the quantization box are expanded into a Fourier series and are related with each other by the scattering matrix of the system, which is the product of matrices describing the propagation of plane waves in empty regions of the quantization box and the scattering matrix of the photonic structure (or an arbitrary inhomogeneity). The quantization condition (similarly to the onedimensional case) is formulated as follows: the eigenvalues of the scattering matrix are equal to unity, which corresponds to the fact that the set of waves that are incident on the structure (components of the expansion into the Fourier series) is equal to the set of waves that travel away from the structure (outgoing waves). The coefficients of the matrix of scattering through the inhomogeneous structure have been calculated using the following procedure: the structure is divided into parallel layers such that the permittivity in each layer varies only along the axis that is perpendicular to the layers. Using the Fourier transform, the Maxwell equations have been written in the form of a matrix that relates the Fourier components of the electric field at the boundaries of neighboring layers. The product of these matrices is the transfer matrix in the basis of the Fourier components of the electric field. Represented in a block form, it is composed by matrices that contain the reflection and transmission coefficients for the Fourier components of the field, which, in turn, constitute the scattering matrix. The developed method considerably simplifies the calculation scheme for the analysis of the behavior of the electromagnetic field in structures with a two-dimensional inhomogeneity. In addition, this method makes it possible to obviate difficulties that arise in the analysis of the Purcell effect because of the divergence of the integral describing the effective volume of the mode in open systems.

The quantum-statistical properties of states of an electromagnetic field of general superpositions of coherent states of the form of N_α,β(α⌤+e^iξ β⌤ are investigated. Formulas for the fluctuations (variances) of Hermitian trigonometric phase field operators Ŝ ≡ côs φ, Ĉ ≡ sîn φ (the so-called “Susskind–Glogower operators”) are found. Expressions for the rigorous uncertainty relations (Cauchy inequalities) for operators of the number of photons and trigonometric phase operators, as well as for operators Ŝ and Ĉ, are found and analyzed. The states of amplitude \({N_{\alpha ,\beta }}\left( {\left| {{{\sqrt {ne} }^{i\varphi }}\rangle + {e^{i\xi }}\left| {{{\sqrt {{n_\beta }e} }^{i\varphi }}\rangle } \right.} \right.} \right)\), φ = φ_α = φ_β, and phase \({N_{\alpha ,\beta }}\left( {\left| {{{\sqrt {ne} }^{i{\varphi _\alpha }}}\rangle + {e^{i\xi }}\left| {{{\sqrt {ne} }^{i{\varphi _\beta }}}\rangle } \right.} \right.} \right)\), n = n_α = n_β, superpositions of coherent states are considered separately. The types of quantum superpositions of meso- and macroscales (n_α, n_β » 1) are found for which the sines and/or cosines of the phase of the field can be measured accurately, since, under certain conditions, the quantum fluctuations of these quantities are close to zero. A simultaneous accurate measurement of cosφ and sinφ is possible for amplitude superpositions, while an accurate measurement of one of these trigonometric phase functions is possible in the case of certain phase superpositions. Amplitude superpositions of coherent states with a vacuum state are quantum states of the field with a “maximum” level of the quantum uncertainty both in the case of a mesoscopic scale and in the case of a macroscopic scale of the field with an average number of photons n_α/β ≈ 0, n_β/α » 1.

The equations of electrodynamics in a rotating isotropic homogeneous dielectric are obtained in a covariant form in coordinates of a reference frame that accompanies the rotation of the dielectric. It is found from these equations, which have variable coefficients, that the medium of the rotating dielectric is anisotropic and inhomogeneous. To derive tensors of the electromagnetic field in a rotating reference frame (RRF), the fields and inductions of a virtual inertial reference frame (IRF) that instantaneously accompanies the motion of one of the points of the dielectric are used twice. Initially, using instantaneous local relations, they are expressed in terms of real fields and inductions of the rotating medium, and then they are transformed into fields and inductions of a stationary IRF, in which they are used as components of the tensors of the electromagnetic field. Thus, the electromagnetic field tensors in the IRF are determined taking into account a priori unknown real inhomogeneous permittivity \(\bar \varepsilon \) and permeability \(\bar \varepsilon \) of the rotating medium. At the final stage, the tensors in the RRF are obtained by transformation rules for covariant and contravariant tensor components in accordance with known analytical relationships of fixed and rotating coordinates. The properties of modes of a rotating ring resonator in the form of homogeneous TE waves that travel along and against the direction of rotation and, in particular, their normal frequencies are examined. The contribution of inhomogeneous properties of the medium of a rotating dielectric to the difference between the normal frequencies of the counterpropagating waves (to the Sagnac effect) is determined. In a solid material with known elastic and striction characteristics, its density and dielectric permittivity depend on the radial coordinate. These dependences are caused by the action of the centrifugal force and changes in the polarization and magnetization of the medium because of the rotational motion of charged particles. The coordinate dependences of permittivity \(\bar \varepsilon \) and permeability \(\bar \varepsilon \) make additional contributions to the inhomogeneous properties of the medium of the rotating dielectric and to the Sagnac effect.

A specific feature of scanning Fourier-transform IR spectroradiometers (FTIR SRs) is the use of a multiarea photodetector. The optical scheme of these SRs is calculated so as to provide the most efficient transfer of the IR radiation from each sector of the IR channel to the corresponding element of the multiarea photodetector. An indirect method is proposed, which makes it possible to estimate the alignment quality of the IR channel of a scanning FTIR SR based on the calculation of its characteristic instrumental functions, which should eventually provide the best sensitivity for the entire multiarea photodetector of scanning FTIR SR.