JETP Letters最新文献_第8页

Interpretation of the Transition from Absorption to Amplification in an Electric Field of Resonant Terahertz Reflection in Graphene Sandwiches and Prospects for Creating a Universal Terahertz Sandwich Laser 石墨烯夹层共振太赫兹反射电场中从吸收到放大转变的解释和创造通用太赫兹夹层激光器的前景

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-07-08 DOI: 10.1134/S0021364025610437

A. A. Andronov, V. I. Pozdnyakova

{"title":"Interpretation of the Transition from Absorption to Amplification in an Electric Field of Resonant Terahertz Reflection in Graphene Sandwiches and Prospects for Creating a Universal Terahertz Sandwich Laser","authors":"A. A. Andronov, V. I. Pozdnyakova","doi":"10.1134/S0021364025610437","DOIUrl":"10.1134/S0021364025610437","url":null,"abstract":"<p>The performed calculations and discussions have explained the mechanisms of terahertz radiation reflection from high-quality graphene sandwiches (coated with hexagonal boron nitride layers) with stripline resonators and an electric field and current in graphene in an experiment carried out by the group led by Taiichi Otsuji. In that experiment, a decrease in the frequency and the suppression of terahertz resonances in the strips to their disappearance were observed with an initial increase in the field strength and the emergence of resonances with increasing frequency and amplification was observed in high fields. It is demonstrated in this work that resonance suppression in low fields is caused by the Dirac relation between the electron velocity and the momentum in graphene and by diffusional heating of electrons with increasing temperature. The emergence of resonances with amplification in high fields is caused by the transition to dynamic heating (streaming) of electrons in graphene, where the main electron dynamic processes are motion in the electric field and the emission of optical phonons. Our calculations show that a negative terahertz conductivity (with frequencies dependent on the electric field) and a positive additive to the real part of the graphene response with a region where it increases with the frequency arise in graphene under these conditions. This leads to the observed increase in resonance frequencies with the field and amplification at the resonances. These observations and our analysis provide a realistic basis for creating a cw terahertz laser at room temperature, tunable in frequency by an electric field over a wide range (1–10 THz), based on such sandwiches, without stripline resonators.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"123 11","pages":"749 - 755"},"PeriodicalIF":1.1,"publicationDate":"2026-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148394765","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

Phase Transformations and Elastic Properties of Ethanol, Methanol, and CH3OH:C2H5OH Binary Systems at Low Temperatures and High Pressures 低温高压下乙醇、甲醇和CH3OH:C2H5OH二元体系的相变和弹性性能

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-07-08 DOI: 10.1134/S0021364026606792

E. L. Gromnitskaya, I. V. Danilov, V. V. Brazhkin

引用次数: 0

Fast Ignition Targets for Modern Inertial Confinement Fusion Experiments 现代惯性约束聚变实验的快速点火靶

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-06-30 DOI: 10.1134/S0021364026600953

S. Yu. Gus’kov, N. N. Demchenko, R. A. Yakhin

引用次数: 0

Effect of the Local Field and Dipole–Dipole Interaction on the Spontaneous Ordering of Dipole Moments in Bismuth Monolayers with an Orthorhombic Structure 局域场和偶极-偶极相互作用对正交结构铋单分子层偶极矩自发有序的影响

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-06-30 DOI: 10.1134/S0021364026601004

D. V. Ponkratova, I. V. Zagorodnev, V. V. Enaldiev

{"title":"Effect of the Local Field and Dipole–Dipole Interaction on the Spontaneous Ordering of Dipole Moments in Bismuth Monolayers with an Orthorhombic Structure","authors":"D. V. Ponkratova, I. V. Zagorodnev, V. V. Enaldiev","doi":"10.1134/S0021364026601004","DOIUrl":"10.1134/S0021364026601004","url":null,"abstract":"<p>Using two complementary approaches, the instability of bismuth monolayers with an orthorhombic structure with respect to the emergence of spontaneous electric dipole moments at the crystal lattice sites has been studied. The first approach, based on determining the dipole moments of lattice sites through the polarizability of bismuth atoms and taking into account the local Lorentz–Lorenz field, suggests the possibility of the existence of several antiferroelectric and ferroelectric phases in orthorhombic bismuth monolayers. Using the second approach, the vibrational spectrum of a nonpolar symmetric lattice has been analyzed, and two types of soft optical modes corresponding to the ferroelectric and antiferroelectric instabilities of the monolayers have been revealed. The relationship of the Born effective charges to the polarization direction in the ferroelectric phase, as well as their role in the reduction of the frequency of the polar optical phonon, which characterizes the lattice deformation in the ferroelectric phase due to the dipole–dipole interaction, has been shown.</p>","PeriodicalId":604,"journal":{"name":"JETP Letters","volume":"123 10","pages":"714 - 719"},"PeriodicalIF":1.1,"publicationDate":"2026-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148349771","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

Evaluation of the Terahertz Radiation Spectrum Using a Fresnel Zone Plate 用菲涅耳带片评价太赫兹辐射频谱

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-06-30 DOI: 10.1134/S0021364026601107

N. A. Khasiiatullov, D. E. Shipilo, I. A. Nikolaeva, G. E. Rizaev, N. A. Panov, O. G. Kosareva, L. V. Seleznev

引用次数: 0

Multiphoton Resonant Excitation and High Harmonic Generation in Large Graphene Quantum Dots 大石墨烯量子点的多光子共振激发和高谐波产生

IF 1.1 4区物理与天体物理

JETP Letters Pub Date : 2026-06-30 DOI: 10.1134/S0021364026600874

Kh. V. Sedrakian, A. G. Ghazaryan, A. A. Markosyan

引用次数: 0

On the Generation of Resonant Dispersion Waves in a Quartz Capillary 石英毛细管中共振色散波的产生