JETP Letters最新文献_第2页

Features of Resonant Raman Scattering in Superhard Amorphous Carbon

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S0021364024603397

M. Yu. Popov, F. S. Khorobrykh, S. A. Klimin, D. A. Ovsyannikov

{"title":"Features of Resonant Raman Scattering in Superhard Amorphous Carbon","authors":"M. Yu. Popov, F. S. Khorobrykh, S. A. Klimin, D. A. Ovsyannikov","doi":"10.1134/S0021364024603397","DOIUrl":"10.1134/S0021364024603397","url":null,"abstract":"The resonant Raman scattering phenomena in carbon nanoclusters formed by sp3 bonds have been investigated. Such structures have been synthesized from fullerite С60 at pressures of 20–25 GPa at room temperature and under heating to 1400 K. Two types of Raman resonance are observed. The first type is associated with the resonant enhancement of the Raman spectra near the absorption edge and has been observed for the prepared samples under laser excitation at wavelengths of 1064 and 532 nm. In such spectra, high-frequency sp3 modes of all nanoclusters from 1388 to 1640 cm–1 are observed. The second type of resonance manifests itself in the activation of one of the modes in the range of 1388–1640 cm–1 of the Raman spectrum, depending on the exciting-radiation wavelength. The frequency of the active mode is a linear function of the exciting-radiation wavelength. The piezospectroscopy method has been used to show that under the excitation with a shorter wavelength, clusters with a larger bulk compression modulus are involved in the Raman scattering processes.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 8","pages":"589 - 592"},"PeriodicalIF":1.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Detection of Resonant Collisional Radiative Transfer of the Vibrational Energy between Molecules Subjected to Infrared Laser Multiphoton Excitation in a Two-Component Medium

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S0021364024603506

G. N. Makarov, A. N. Petin

{"title":"Detection of Resonant Collisional Radiative Transfer of the Vibrational Energy between Molecules Subjected to Infrared Laser Multiphoton Excitation in a Two-Component Medium","authors":"G. N. Makarov, A. N. Petin","doi":"10.1134/S0021364024603506","DOIUrl":"10.1134/S0021364024603506","url":null,"abstract":"Resonant collisional radiative transfer of the vibrational energy between molecules subjected to infrared laser multiphoton excitation in a two-component medium has been studied. Experiments have been carried out with BCl3 molecules of the natural isotopic composition in a mixture with CH3F molecules, which are optically active sensitizers and acceptors of radicals. Both types of molecules resonantly absorb laser radiation. Resonant collisional radiative energy transfer from CH3F molecules to 10BCl3 ones has been observed. It has been shown that this process significantly increases the dissociation yield of 10BCl3 and 11BCl3 molecules compared to the dissociation yield with neutral acceptors of radicals. Dependences of the dissociation yields of BCl3 molecules on the pump laser frequency have demonstrated a structure that closely correlates with the structure of the infrared absorption spectrum of CH3F molecules. The method has been described and the experimental results have been reported. Conditions for efficient resonant collisional radiative transfer of the vibrational energy between molecules subjected to infrared laser multiphoton excitation have been discussed.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 8","pages":"593 - 598"},"PeriodicalIF":1.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nonequilibrium Heating of Electrons, Melting, and Modification of a Nickel Nanofilm by an Ultrashort Terahertz Pulse

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S002136402460349X

S. I. Ashitkov, P. S. Komarov, A. V. Ovchinnikov, S. A. Romashevskiy, E. V. Struleva, O. V. Chefonov, M. B. Agranat

引用次数: 0

Influence of Anisotropy on the Study of the Critical Behavior of Spin Models by Machine Learning Methods

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S0021364024603440

D. D. Sukhoverkhova, L. N. Shchur

{"title":"Influence of Anisotropy on the Study of the Critical Behavior of Spin Models by Machine Learning Methods","authors":"D. D. Sukhoverkhova, L. N. Shchur","doi":"10.1134/S0021364024603440","DOIUrl":"10.1134/S0021364024603440","url":null,"abstract":"In this paper, we applied a deep neural network to study the issue of knowledge transferability between statistical mechanics models. The following computer experiment was conducted. A convolutional neural network was trained to solve the problem of binary classification of snapshots of the Ising model’s spin configuration on a two-dimensional lattice. During testing, snapshots of the Ising model spins on a lattice with diagonal ferromagnetic and antiferromagnetic connections were fed to the input of the neural network. Estimates of the probability of samples belonging to the paramagnetic phase were obtained from the outputs of the tested network. The analysis of these probabilities allowed us to estimate the critical temperature and the critical correlation length exponent. It turned out that at weak anisotropy the neural network satisfactorily predicts the transition point and the value of the correlation length exponent. Strong anisotropy leads to a noticeable deviation of the predicted values from the precisely known ones. Qualitatively, strong anisotropy is associated with the presence of oscillations of the correlation function above the Stefenson disorder temperature and further approach to the point of the fully frustrated case.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 8","pages":"616 - 621"},"PeriodicalIF":1.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0021364024603440.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778458","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Critical Temperature and Order Parameter in Superconducting Heterostructures with Allowance for a Nonzero Coupling Constant in a Polydomain Ferromagnet

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S0021364024603191

V. A. Tumanov, Yu. N. Proshin

{"title":"Critical Temperature and Order Parameter in Superconducting Heterostructures with Allowance for a Nonzero Coupling Constant in a Polydomain Ferromagnet","authors":"V. A. Tumanov, Yu. N. Proshin","doi":"10.1134/S0021364024603191","DOIUrl":"10.1134/S0021364024603191","url":null,"abstract":"The superconducting state in heterostructures containing layers of a superconductor and a ferromagnet, which is split into domains, has been studied taking into account the long-range electron–electron interaction in the ferromagnetic layer. The critical temperature and spatial distribution of the order parameter in different heterostructures have been calculated. Various types of spin valves have been examined, including a valve based on solitary reentrant superconductivity in asymmetric superconductor/superconductor/superconductor systems. A shift of the minimum has been observed in the dependence of the critical temperature of the superconductor/superconductor/superconductor system on the thickness of the ferromagnetic layer due to the presence of a domain structure. A state with alternating signs of the phase of the superconducting order parameter in one of the superconducting layers against the background of domain walls has been obtained. In superconductor/superconductor/superconductor systems, the alternation of the phase sign is also possible at the edge of one of the ferromagnetic layers because of the alternation of the magnetization direction. The possibility of using the sensitivity of the order parameter phase to magnetic inhomogeneities to create a controllable 0–π Josephson junction is discussed.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 8","pages":"608 - 615"},"PeriodicalIF":1.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1134/S0021364024603191.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Second Harmonic Generation Accompanied by the Formation of Intense Light Bullets

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S0021364024601453

S. V. Sazonov

引用次数: 0

Infrared Transmission Spectra of TiS3: Fundamental Absorption Edge, Phonons, and Excitons

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-12-04 DOI: 10.1134/S002136402460335X

K. N. Boldyrev, E. V. Mostovshchikova, A. N. Titov, V. Ya. Pokrovskii, I. G. Gorlova

引用次数: 0

Structural Diversity and Phase Transitions in Mg2 – xMn1 + xBO5 (x = 0.0, 0.2, 0.4) Borates with a Mixed Valence 混合价硼酸盐 Mg2 - xMn1 + xBO5 (x = 0.0, 0.2, 0.4) 中的结构多样性和相变

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-11-12 DOI: 10.1134/S0021364024603075

N. A. Belskaya, N. V. Kazak, A. D. Vasiliev, E. V. Eremin, E. M. Moshkina, D. A. Velikanov, L. N. Bezmaternykh, S. Yu. Gavrilkin, S. G. Ovchinnikov

{"title":"Structural Diversity and Phase Transitions in Mg2 – xMn1 + xBO5 (x = 0.0, 0.2, 0.4) Borates with a Mixed Valence","authors":"N. A. Belskaya, N. V. Kazak, A. D. Vasiliev, E. V. Eremin, E. M. Moshkina, D. A. Velikanov, L. N. Bezmaternykh, S. Yu. Gavrilkin, S. G. Ovchinnikov","doi":"10.1134/S0021364024603075","DOIUrl":"10.1134/S0021364024603075","url":null,"abstract":"Single and polycrystalline samples of Mg2 – xMn1 + xBO5 (x = 0.0, 0.2, 0.4) oxyborates have been obtained for the first time by spontaneous crystallization from the solution–melt and through a solid-state reaction. X-ray diffraction studies have shown that compounds are crystallized with increasing manganese content in the ludwigite (space group Pbam)–hulsite (space group P2/m)–orthopinakiolite (space group Pbam) series and belong to the “3 Å wallpaper” borate family. A common property of materials is the presence of octahedral complexes (walls) consisting of manganese ions with a mixed valence at even crystallographic sites. The dc magnetization and specific heat of the Mg2 – xMn1 + xBO5 (x = 0.0, 0.2, 0.4) compounds have been studied for the first time. These studies have shown that cooling is accompanied by magnetic transitions, which are due to the ordering of several magnetic subsystems.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 7","pages":"509 - 516"},"PeriodicalIF":1.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Bound States of High-Order Magnetic Skyrmions and a Superconducting Pearl Vortex 高阶磁性 Skyrmions 和超导珍珠涡旋的边界态

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-11-12 DOI: 10.1134/S0021364024602896

A. D. Fedoseev, M. S. Shustin, D. M. Dzebisashvili

引用次数: 0

Ramsey Spectroscopy of CPT Resonances on the D1 Line of Alkali Metal Atoms in Miniature Cells in the Field of Counterpropagating Waves with Opposite Circular Polarizations 微型电池中碱金属原子 D1 线的 CPT 共振在相反圆极化反向传播波场中的拉姆齐光谱分析

IF 1.4 4区物理与天体物理

JETP Letters Pub Date : 2024-11-12 DOI: 10.1134/S0021364024603130

V. I. Yudin, M. Yu. Basalaev, D. A. Radnatarov, I. V. Gromov, M. D. Radchenko, S. M. Kobtsev, A. V. Taichenachev

{"title":"Ramsey Spectroscopy of CPT Resonances on the D1 Line of Alkali Metal Atoms in Miniature Cells in the Field of Counterpropagating Waves with Opposite Circular Polarizations","authors":"V. I. Yudin, M. Yu. Basalaev, D. A. Radnatarov, I. V. Gromov, M. D. Radchenko, S. M. Kobtsev, A. V. Taichenachev","doi":"10.1134/S0021364024603130","DOIUrl":"10.1134/S0021364024603130","url":null,"abstract":"In this study, the Ramsey spectroscopy of coherent population trapping resonances excited on the D1 line of alkali metal atoms in miniature vapor cells has been studied theoretically and experimentally. The configuration of the field produced by two counterpropagating waves with opposite circular polarizations has been considered. A counterpropagating wave is formed as a result of reflection from a partially transmitting output mirror, while the signal from the initial wave transmitted through the mirror is detected. It is shown that such a scheme is characterized by the optimal mirror reflection coefficient, for which the short-term stability can be substantially improved relative to the standard scheme without the counterpropagating wave. The three-fold improvement of the short-term stability of the atomic clock based on the coherent population trapping resonance in a vapor cell with 87Rb atoms has been demonstrated experimentally.","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"120 7","pages":"477 - 482"},"PeriodicalIF":1.4,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142600620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0