Bulletin of the Russian Academy of Sciences: Physics最新文献

The spectral and kinetic characteristics of conjugates of Ce_0.50Y_0.35Tb_0.15F₃ nanoparticles with chlorin e-6 (Photoran) were studied. Effective nonradiative energy transfer from nanoparticles to e-6 chloride molecules is shown. Cytotoxic properties of conjugates induced by exposure to X-ray radiation against human lung adenocarcinoma cells A549 have been characterized.

We presented the results of a numerical analysis of frequency entanglement in the context of generating multidimensional hybrid-entangled states of biphotons, proposed by the authors earlier. The results presented will be useful for researchers in the field of quantum optics to understand the internal structure of entanglement of hybrid two-photon states of light and the possibility of controlling these states.

An optical quantum memory protocol is implemented in schemes of silenced echo revival in a ¹⁶⁷Er³⁺:Y₂SiO₅ crystal at a telecommunication wavelength. The signal pulse recovery efficiency is 13% at a storage time of 60 μs for the optimum intensity of rephasing laser pulses. With a further increase in the laser pulse intensity, a superradiance pulse appears, causing a decrease in the signal pulse recovery efficiency. A way of improving the quantum memory efficiency by further increasing the pulse area of rephasing pulses is discussed.

The authors propose and test a quantum key distribution scheme with independent detection using sideband encoding and a Sagnac interferometer. The scheme provides automatic compensation for phase fluctuations in optical channels and demonstrates stable interference of weak coherent states over a 25-km link with a low error rate, confirming it can be used to build secure quantum networks.

The angular velocity of microparticles moving along a vortex light ring in an optothermal trap was experimentally demonstrated to be higher than that in an optical trap with the same trap parameters. It was shown that this velocity can be controlled without increasing radiation power on the light ring. The data obtained were analyzed based on the results of numerical simulation for the distribution of temperature and convection flow velocity over the sample area.

Results are presented from studying the optical characteristics of nanostructured surfaces obtained via electrochemical deposition in pores of track-etched membranes. Such structures display a pronounced effect of enhancing Raman scattering from the molecules adsorbed on their surface. Rhodamine 6G and Malachite Green dyes are used as model compounds to estimate the efficiency of enhancement. The dependence between the parameters of synthesis of nanowires and the degree of signal enhancement is established experimentally, allowing the optimum conditions for obtaining SERS-active substrates to be determined.

A model of scattering in disperse media has been developed considering secondary scattering. It has been found that the main reasons for the disturbance of monotonicity are the existence of optical inhomogeneities in the medium and the fact that the light scattered primarily by optical inhomogeneities of the medium undergoes secondary scattering by the dispersed phase.

The authors study the behavior of the Raman spectra of titanium foils after they come into contact with a fluorine–gas mixture. It is shown that the bands at 905, 1795, and 2680 cm⁻¹ correspond to fluorine under a titanium oxide nanofilm. The contact between such a foil and humid air reduces the intensity of these bands, while those of titanium oxynitrides and oxyfluorides emerge and grow brighter.

Nanophotonic (photonic crystal) cavities with high Q factor and low mode volume are promising for research in the field of on-chip nonlinear and quantum optics on a crystal. In this paper, the Q factor, mode area, mode volume, and Purcell factor of a nanophotonic cavity based on silicon and silicon nitride are calculated to generate high-Q resonant states.

The electron paramagnetic resonance spectra of Mn²⁺ and Gd³⁺ ions in crystals of the narrow-gap semiconductor Pb_0.996Cu_0.003Mn_xGd_yS (x ( approx ) 6 × 10^–4, y ( approx ) 4 × 10^–4) were discovered to demonstrate an unusually strong dependence of the spin relaxation processes of these ions on temperature and power of X-band microwave radiation acting on the crystal sample in a magnetic field. The observed effect manifests itself as sharp dependences of the line shape parameters of the EPR spectra of Mn²⁺ and Gd³ ions on temperature and microwave power. The results of the experimental study indicate a high efficiency of the exchange interaction between these ions via free charge carriers.