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Термодинамика симметричной спин-орбитальной модели: одномерный и двумерный случаи
Письма в Журнал экспериментальной и теоретической физики. 2019. Т. 109. № 8. С. 557-563.
The specific heat and susceptibilities for the two- and one-dimensional spin–orbital models are calculated in
the framework of a spherically symmetric self-consistent approach at different temperatures and relations
between the parameters of the system. It is shown that, even in the absence of the long-range spin and orbital
order, the system exhibits features in the behavior of thermodynamic characteristics typical of those manifesting
themselves at phase transitions. Such features are attributed to the quantum entanglement of the coupled
spin and orbital degrees of freedom.
Malkin B., Elena A. Popova, Chukalina E. et al., Physica Status Solidi - Rapid Research Letters 2020 Vol. 14 No. 3 P. 190063-1-190063-5
Magnetic properties of antiferromagnetic quasi‐one‐dimensional YFe3(BO3)4 crystals are studied based on the analysis of the measured optical spectra of the Fe3+ ions in different rare‐earth iron borates and self‐consistent four‐particle cluster approach to helical iron chains. Parameters of crystal fields affecting the Fe3+ ions are calculated in the framework of exchange charge model. Parameters of ...
Added: October 30, 2019
Klimin S. A., Popova E., Popova M. N., Journal of Physics: Conference Series 2019 Vol. 1389 No. 1 P. 012039
We present low-temperature far-infrared study of Sm2BaNiO5. The lowest-frequency phonon of Sm2BaNiO5 generated by the motion of the Sm3+ ion demonstrates anomalous behaviour at temperatures lower than the Néel temperature, T<TN=55 K. This phonon hardens at the magnetic ordering although its frequency shift does not follow the magnetic order parameter. The observed phenomenon is responsible for ...
Added: December 19, 2019
Khaydukov Y. N., Vasenko A. S., Kravtsov E. A. et al., Physical Review B: Condensed Matter and Materials Physics 2018 Vol. 97 No. 144511 P. 144511-1-144511-8
We report on a study of the structural, magnetic and superconducting properties of Nb(25nm)/Gd(df)/Nb(25nm) hybrid structures of a superconductor/ ferromagnet (S/F) type. The structural characterization of the samples, including careful determination of the layer thickness, was performed using neutron and X-ray scattering with the aid of depth sensitive mass-spectrometry. The magnetization of the samples was ...
Added: April 9, 2018
Pudalov V., Physics-Uspekhi 2017 Т. 187 № 4 С. 450-462
We discuss the synthesis, characterization, and comprehensive study of Ba-122 single crystals with various substitutions and various superconducting transition temperatures. We use five complementary techniques to obtain a self-consistent set of data on the superconducting properties of Ba-122. A major conclusion of our work is the coexistence of two superconducting condensates differing in the electron±boson ...
Added: August 4, 2018
Valiulin V., Mikheyenkov A., Chtchelkatchev N. et al., SCIPOST PHYSICS 2023 Vol. 6 Article 025
The Kugel–Khomskii model with entangled spin and orbital degrees of freedom is a good testing ground for many important features in quantum information processing, such as robust gaps in the entanglement spectra. Here, we demonstrate that the entanglement can be also robust under effect of temperature within a wide range of parameters. It is shown, in particular, that the ...
Added: May 4, 2023
Antonov V., Gurev V., Kulakov V. et al., PHYSICAL REVIEW MATERIALS 2019 Vol. 3 No. 11 Article 113604
An isobar x(T) of deuterium solubility in iron is constructed at P = 6.3 GPa and 100 ≤ T ≤ 800 °C based on the results of thermal desorption analysis of FeDx samples produced by quenching under high D2 pressure to the temperature of liquid nitrogen. The experiment confirms the value of x = 0.64 ...
Added: October 24, 2021
Bristol : IOP Publishing, 2019
We present low-temperature far-infrared study of Sm2BaNiO5. The lowest-frequency phonon of Sm2BaNiO5 generated by the motion of the Sm3+ ion demonstrates anomalous behaviour at temperatures lower than the Néel temperature, T<TN=55 K. This phonon hardens at the magnetic ordering although its frequency shift does not follow the magnetic order parameter. The observed phenomenon is responsible for ...
Added: October 30, 2019
Khokhlov D. A., Rakhmanov A. L., Rozhkov A. V. et al., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 101 No. 23 P. 235141
A few years ago we predicted theoretically that in systems with nesting of the Fermi surface the spin-valley half-metal has lower energy than the spin density wave state. In this paper we suggest a possible way to distinguish these phases experimentally. We calculate the dynamical spin susceptibility tensor for both states in the framework of ...
Added: October 27, 2020
Burovskiy E., Ikhsanov R., Kuznetsov A. et al., Journal of Physics: Conference Series 2019 Vol. 1163 No. 012046 P. 012046-1-012046-5
We consider a quasi-one-dimensional model of a two-component Fermi gas at zero temperature on one, two and three-leg attractive-U Hubbard ladders. We construct the grand canonical phase diagram of a two-component spin-polarized gas. We find that the structure of the phase diagram of the attractive-U Hubbard model for two and three leg ladders significantly differs ...
Added: April 15, 2019
Редин В. В., Никифоров К. Г., Bondarenko G., Перспективные материалы 2008 № 4 С. 29-33
Исследованы процессы образования нанокластеров, связанные с введением атомов магнитного компонента — хрома и марганца — в гранецентрированную кубическую решетку шпинели CdIn2S4 и тетрагональную решетку халькопирита CuInSe2, соответственно. Рассчитана вероятность существования кластеров различного типа в зависимости от концентрации магнитного компонента. Получены концентрационные зависимости числа кластеров и температурные зависимости обусловленной ими магнитной восприимчивости спиновых стекол CdIn2S4: Cr ...
Added: January 4, 2013
Vagov A., Wolf S., Croitoru M. et al., Communications Physics 2020 Vol. 3 Article 58
Experiments with the crossover superconductors between standard types I and II revealed exotic magnetic flux patterns where Meissner domains coexist with islands of the vortex lattice as well as with vortex clusters and chains. Until now a comprehensive theory for such configurations has not been presented. We solve this old-standing fundamental problem by developing an approach ...
Added: February 24, 2022
Budkov Y., Kolesnikov A. L., Polymer Science - Series C 2018 Vol. 60 No. Supplement 1 P. 148-159
Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the ...
Added: November 30, 2018
Kalmykov A., Melentiev P., Balykin V., Laser Physics Letters 2020 Vol. 17 No. 4 P. 045901
In this paper we present measurements and comparison of SPP propagation length at the practically important telecom wavelength (1560 nm) as well as in the near-infrared and visible spectral ranges. The measurements were carried out for plane SPP waves excited on Ag film surface using optical microscopy of SPP waves in the far field. We ...
Added: January 15, 2021
Antipov A., Seleznev V., Vakhtomin Y. et al., IOP Conference Series: Materials Science and Engineering (MSE) 2020 Vol. 781 No. 1 P. 012011-1-012011-5
Spectral characteristics of WSi and NbN superconducting single-photon detectors with different surface resistance and width of nanowire strips have been investigated in the wavelength range of 1.3-2.5 µm. WSi structures with narrower strips demonstrated better performance for detection of single photons in longer wavelength range. The difference in normalized photon count rate for such structures ...
Added: December 10, 2020
M. : Faculty of Physics, MSU, 2017
The Low Temperature Physics Conference is an international event held every three years, under the auspices of the IUPAP through its Commission C5 on Low Temperature Physics. The aim of these conferences is to exchange information and views among the members of the international scientific community in the general field of Low Temperature Physics. It ...
Added: October 1, 2017
Boldyrev K., Романов А., Хаула Е. et al., Journal of the American Ceramic Society 2019 Vol. 102 No. 5 P. 2745-2751
Single crystal of TlCl was doped with NIR photoluminescent univalent bismuth cations by prolonged immersion in liquid bismuth metal. The ion exchange Tl+ + Bi0 ↔ Tl0 + Bi+ at the crystal surface with subsequent Bi+ migration to the bulk are expected to drive the doping process. Contrary with Bi‐doped TlCl crystals, grown by Bridgman method, the ion exchange does ...
Added: February 8, 2019
Казанцев Д. В., Казанцева Е. А., Кузнецов Е. В. et al., Известия РАН. Серия физическая 2017 Т. 81 № 12 С. 1709-1714
Описаны принципы работы безапертурного сканирующего микроскопа ближнего оптического поля (ASNOM). Зондом в приборе служит металлизированная игла атомно-силового микроскопа, и оптическое взаимодействие с объектами на поверхности локализовано вблизи ее острия размером в несколько нанометров. Тело иглы имеет длину в несколько микрон, и это обеспечивает высокую эффективность ее электромагнитного взаимодействия с падающими на нее извне и излучаемыми ...
Added: December 6, 2020
Bodrova A., Osinsky A., Brilliantov N., Scientific Reports 2020 Vol. 10 Article 693
We study analytically and numerically the distribution of granular temperatures in granular mixtures for
different dissipation mechanisms of inelastic inter-particle collisions. Both driven and force-free systems
are analyzed. We demonstrate that the simplified model of a constant restitution coefficient fails to
predict even qualitatively a granular temperature distribution in a homogeneous cooling state. At the
same time we reveal ...
Added: February 25, 2020
Dziom V., Shuvaev A. V., Shchepetilnikov A. et al., Physical Review B: Condensed Matter and Materials Physics 2019 Vol. 99 No. 4 Article 045305
The integer quantum Hall effect is a well-studied phenomenon at frequencies below about 100 Hz. The plateaus in high-frequency Hall conductivity were experimentally proven to retain up to 33 GHz, but the behavior at higher frequencies has remained largely unexplored. Using continuous-wave terahertz spectroscopy, the complex Hall conductivity of GaAs/AlGaAs heterojunctions was studied in the ...
Added: December 11, 2020
A.Aronin, Abrosimova G., Materials Letters 2017 Vol. 206 P. 64-66
To obtain a correct estimate of the microhardness dependence on the size of nanocrystals, the microhardness
of amorphous-nanocrystalline samples with the same fraction of the crystalline phase and the same
composition of the amorphous matrix but different sizes of nanocrystals was studied. It is shown that the
dependence of microhardness on the nanocrystal size in the size range ...
Added: February 22, 2018
K. I. Kugel, Bianconi A., Poccia N. et al., Superconductor Science and Technology 2015 Vol. 28 No. 2 P. 024005-1-024005-8
The arrested nanoscale phase separation in a two-band Hubbard model for strongly correlated charge carriers is shown to occur in a particular range in the vicinity of the topological Lifshitz transition, where the Fermi energy crosses the bottom of the narrow band and a new sheet of the Fermi surface related to the charge carriers ...
Added: March 12, 2016
Демин А. С., Масляев С. А., Пименов В. Н. et al., Физика и химия обработки материалов 2017 № 6 С. 5-17
Изучено влияние облучения в установке Плазменный фокус PF-1000 экстремальными энергетическими потоками быстрых ионов дейтерия (Ei≈100 кэВ, плотность мощности qi≈1011-1012 Вт/см2, длительность импульса ti≈10-50 нс) и дейтериевой плазмы (qpl≈109- 1010 Вт/см2, tpl≈50-100 нс) на структуру поверхностного слоя молибденовой пластины с учетом его плавления, частичного испарения и закалки расплава. На облученной поверхности обнаружено образование капельных структур, пор, ...
Added: December 25, 2017
Kuzmichev S. A., Kuzmicheva T. E., Tchesnokov S. N. et al., Journal of Superconductivity and Novel Magnetism 2016 Vol. 29 No. 4 P. 1111-1116
We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB2. The experimental L,S(T ) are wellfitted with a two-gap model based on Moskalenko and Suhl system of equations (supplemented with a BCS integral renormalization). From the fitting procedure, we estimate the key ...
Added: March 19, 2016
Бланк В. Д., Boldyrev K., Денисов В. Н. et al., Physical Review B: Condensed Matter and Materials Physics 2020 Vol. 102 P. 115153-1-115153-10
The electronic band structure of the phosphorus-doped high-quality high-pressure and high-temperature–
grown single crystal diamond was studied by infrared absorption, magneto- and electron paramagnetic resonance
spectroscopy, and first-principles calculations. The complete picture of the 1s → np± and 1s → np0 (n = 2, 3,
4) donor transitions with new 1s →3p0,4p0 and 1s →4p± transitions allowed us ...
Added: October 22, 2020