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Field-Emission Resonances in Thin Metallic Films: Nonexponential Decrease of the Tunneling Current as a Function of the Sample-to-Tip Distance
Journal of Physical Chemistry C. 2022. Vol. 126. No. 31. P. 13341–13348.
Aladyshkin A. Y., Schouteden K.
Field-emission resonances (FERs) for two-dimensional Pb(111) islands grown on Si(111)7x7 surfaces were studied by low-temperature scanning tunneling microscopy and spectroscopy (STM/STS) in a broad range of tunneling conditions with both active and disabled feedback loop. These FERs exist at quantized sample-to-tip distances Z_n above the sample surface, where n is the serial number of the FER state. By recording the trajectory of the STM tip during ramping of the bias voltage U (while keeping the tunneling current I fixed), we obtain the set of the Z_n values corresponding to local maxima in the derived dZ/dU(U) spectra. This way, the continuous evolution of Z_n as a function of U for all FERs was investigated by STS experiments with active feedback loop for different I. Complementing these measurements by current--distance spectroscopy at a fixed U, we could construct a 4-dimensional I-U-Z-dZ/dU diagram, that allows us to investigate the geometric localization of the FERs above the surface. We demonstrate that (i) the difference \delta Z_n=Z_(n+1)-Z_n between neighboring FER lines in the Z-U diagram is independent of n for higher resonances, (ii) the \delta Z_n value decreases as U increases; (iii) the quantized FER states lead to the periodic variations of ln I as a function of Z with periodicity \delta Z; (iv) the periodic variations in the ln I – Z spectra allows to estimate the absolute height of the tip above the sample surface. Our findings contribute to a deeper understanding on how the FER states affect various types of tunneling spectroscopy experiments and how they lead to a non-exponential decay of the tunneling current as a function of Z at high bias voltages in the regime of quantized electron emission.
Ивченко В. С., Иевлева В. А., Matienko D. et al., Журнал технической физики 2026 № 9 С. 1738–1749
Задача о возбуждении бегущих фонон-поляритонных волн на поверхности полярного кристалла падающей извне световой волной (с частотой, близкой к частоте решеточных колебаний) решена теоретически только для бесконечной открытой поверхности кристалла. В случаях, когда часть поверхности покрыта металлической маской, препятствующей проникновению возбуждающего излучения к атомам среды, и эта маска имеет произвольную форму, общепризнанного решения неоднородной задачи нет. ...
Added: October 20, 2026
Logvenkov S. A., Известия РАН. Механика жидкости и газа 2026 № 3 С. 59–75
The problem of the evolution of cell volume fraction in a spherical aggregate composed of cells,
extracellular matrix, and fluid is considered. The aggregate is surrounded by extracellular matrix. The
problem formulation employs a multiphase model of a biological continuum, previously developed by the
author, consisting of two actively interacting solid phases and a fluid. The propagation of ...
Added: October 20, 2026
Lavrukhina E. A., Krasavin D. P., Krishtopenko S. S. et al., Physical Review B: Condensed Matter and Materials Physics 2026 Vol. 114 No. 22 Article 225414
We study coherent electric manipulation of magnetic field induced localized states at a double kink of a helical edge in a HgTe/CdHgTe quantum well. An in-plane magnetic field opens a gap in the one-dimensional (1D) edge spectrum, while changes in the edge orientation generate localized in-gap states at the kinks. We show that, for suitable ...
Added: October 19, 2026
Смерчанский П. С., Koledov V. V., Kamantsev A. P. et al., Physics of Metals and Metallography 2026 Vol. 127 No. 6-7 P. 689–693
Heusler alloys of the Ni2MnX family, where X = Ga, In, Sn, …, which have been shown to exhibit
giant magnetocaloric effect (MCE) and magnetically controlled shape memory effect due to thermoelastic
magnetostructural phase transition (MSPT), continue to attract attention. However, these functional properties are fully manifested in strong magnetic fields of at least several T. Currently, ...
Added: October 19, 2026
Тукачев Н. В., Bataev V., Abramenkov A. et al., Computational and Theoretical Chemistry 2016 No. 1080 P. 23–32
Electronic state calculations, such as equilibrium geometry parameters, harmonic vibrational frequencies and potential barriers to conformational transitions (as well as conformer energy differences in excited states), using ab initio methods, such as MP2, CCSD(T), CASSCF, CASPT2 and MRCI, were carried out on the formamide molecule in the ground (S0) and the lowest excited singlet (S1) ...
Added: October 14, 2026
Тукачев Н. В., Bataev V. А., Godunov I. А., Journal of Quantitative Spectroscopy and Radiative Transfer 2016 Vol. 177 P. 291–300
For conformers of the N-methylformamide (HCONHCH3) molecule, calculations of equilibrium geometry parameters, harmonic vibration frequencies, energy differences and potential barriers to conformational transitions were performed in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states. In the S0 state, the molecule exists in trans and cis stable conformations (having Cs symmetry). ...
Added: October 14, 2026
Тукачев Н. В., Bataev V. А., Godunov I. А., Journal of Quantitative Spectroscopy and Radiative Transfer 2017 Vol. 192 P. 30–41
For acetamide molecule (CH3CONH2) in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states calculations of equilibrium geometry parameters, harmonic vibrational frequencies and barriers to conformational transitions (also conformer energy differences in excited states) using following ab initio methods: MP2, CCSD(T), CASSCF, CASPT2 and MRCI were performed. One-, two- and three-dimensional ...
Added: October 14, 2026
Тукачев Н. В., Bataev V. A., Godunov I. A., Computational and Theoretical Chemistry 2017 Vol. 1113 P. 82–93
Equilibrium geometry parameters, harmonic vibrational frequencies and barriers to conformational transitions and conformer energy differences for N-methylacetamide (CH3CONHCH3) molecule in S0, S1 and T1 electronic states were calculated in MP2 (S0) and CASPT2 (S1, T1) levels of theory. It is known that there are two planar (or effectively planar) conformers of N-methylacetamide in the ground ...
Added: October 14, 2026
Тукачев Н. В., Maslennikov D., Sosorev A. et al., The Journal of Physical Chemistry Letters 2019 Vol. 10 No. 12 P. 3232–3239
Conformational space of polyphenylenevinylene oligomers is systematically investigated computationally at energies relevant for room temperature dynamics in a solvent and in a solid state. Our calculations show that optimal oligomer structures are essentially planar. However, lack of a deep minimum at the planar geometry allows for large molecular deformations even at very low temperatures. At ...
Added: October 14, 2026
Тукачев Н. В., Akkuratov A., Kuznetsov I. et al., Synthetic Metals 2020 Vol. 259 Article 116231
Four new conjugated polymers based on benzodithiophene, thiophene and 2,1,3-benzothiadiazole or 5,6-difluoro-2,1,3-benzothiadiazole were synthesized and investigated as absorber materials for organic photovoltaics. The effect of (bi)thiophene π-spacers and fluorine substitution on the physicochemical and optoelectronic properties of the polymers was revealed and correlations were drawn with their electrical characteristics in organic solar cells. In particular, ...
Added: October 14, 2026
Тукачев Н. В., Nuraliev M., Parashchuk O. et al., Journal of Chemical Physics 2020 Vol. 153 No. 17 Article 174303
Electron–phonon interaction strongly affects and often limits charge transport in organic semiconductors (OSs). However, approaches to its experimental probing are still in their infancy. In this study, we probe the local electron–phonon interaction (quantified by the charge-transfer reorganization energy) in small-molecule OSs by means of Raman spectroscopy. Applying density functional theory calculations to four series ...
Added: October 14, 2026
Тукачев Н. В., Klimovich I., Prudnov F. et al., Dyes and Pigments 2021 Vol. 185 Article 108899
A series of ten conjugated polymers incorporating in their molecular frameworks extended DADAD building blocks with thiophene donor (D) and either benzotriazole, benzoxadiazole, benzothiadiazole, difluorobenzothiadiazole or quinoxaline acceptor (A) units were synthesized and characterized. The optoelectronic properties of new polymers were computed and experimentally investigated revealing a good relationship, which can guide further rational design ...
Added: October 14, 2026
Тукачев Н. В., Sosorev A., Parashchuk O. et al., Physical Chemistry Chemical Physics 2021 Vol. 23 No. 29 P. 15485–15491
Dynamic disorder manifested in fluctuations of charge transfer integrals considerably hinders charge transport in high-mobility organic semiconductors. Accordingly, strategies for suppression of the dynamic disorder are highly desirable. In this study, we suggest a novel promising strategy for suppression of dynamic disorder—tuning the molecular electrostatic potential. Specifically, we show that the intensities of the low-frequency ...
Added: October 14, 2026
Тукачев Н. В., González-Jiménez M., Ramakrishnan G. et al., Physical Chemistry Chemical Physics 2021 Vol. 23 No. 23 P. 13250–13260
Low-frequency vibrations play an essential role in biomolecular processes involving DNA such as gene expression, charge transfer, drug intercalation, and DNA–protein recognition. However, understanding the vibrational basis of these mechanisms relies on theoretical models due to the lack of experimental evidence. Here we present the low-frequency vibrational spectra of G-quadruplexes (structures formed by four strands ...
Added: October 14, 2026
González-Jiménez M., Barnard T., Russell B. et al., Nature Communications 2023 Vol. 14 Article 215
A common feature of glasses is the “boson peak”, observed as an excess in the heat capacity over the crystal or as an additional peak in the terahertz vibrational spectrum. The microscopic origins of this peak are not well understood; the emergence of locally ordered structures has been put forward as a possible candidate. Here, ...
Added: October 14, 2026
Тукачев Н. В., Mali G., Tassieri M. et al., Journal of the american chemical society 2023 Vol. 145 No. 48 P. 26061–26067
On supercooling a liquid, the viscosity rises rapidly until at the glass transition it vitrifies into an amorphous solid accompanied by a steep drop in the heat capacity. Therefore, a pure homogeneous liquid is not expected to display more than one glass transition. Here we show that a family of single-component homogeneous molecular liquids, titanium ...
Added: October 14, 2026
Тукачев Н. В., Dubinets N. O., Dominskiy D. I. et al., Optical Materials 2024 Vol. 157 No. 2 P. 1–8
Donor-acceptor molecules exhibiting TADF are in the heart of third-generation OLEDs. In this study, we apply (TD)DFT and multiscale modelling to assess the reliability of these approaches for prediction of the emission properties of carbazole-triazine (Cz-TRZ) based TADF luminophores. We found that a series of hybrid and doubly hybrid functionals reproduce the experimentally observed trend ...
Added: October 14, 2026
Тукачев Н. В., Su L., Zhou Y. et al., Polymer 2025 Vol. 326 Article 128336
As the power conversion efficiency (PCE) of organic photovoltaics (OPVs) approximates the 19 % threshold, wide bandgap (WBG) polythiophenes (PTs) have gained increasing attention due to their simple chemical structures and ease of synthesis, making them promising candidates for large-scale production. However, the benchmark polymer poly(3-hexylthiophene) (P3HT) is limited by its high-lying HOMO energy level, which ...
Added: October 14, 2026
Dmitriev A., Kornilov V., Batienkov R., Lecture Notes in Civil Engineering 2026 Vol. 886 P. 249–255
Numerous studies have provided compelling evidence that the probability distribution of avalanche sizes follows a power law, and that 1/f noise is present in the stochastic dynamics of landslides. We present a theoretical explanation of these phenomena within the framework of self-organized criticality theory, proposing a discrete-time model in the form of a sandpile cellular ...
Added: October 13, 2026
Dmitriev A., Shulman I., Lebedev A., Studies in Computational Intelligence 2026 Vol. 1265 P. 266–273
A discrete-time model is presented for the self-organization of the X/Twitter social network to the edge of a phase transition, characterized by avalanche-like propagation of information in the network. The model is based on the analogy between the critical dynamics of the X social network and sandpile cellular automata with Manna rule on the Chung-Lu ...
Added: October 13, 2026
Arutyunov K., Kharitonov I. A., Petrosyants K. O., JETP Letters 2026 Vol. 124 No. 6 P. 1–16
Superconducting properties of metallic micro- and nanowires can be entirely different from those of bulk superconductors. Of particular interest is the nonequilibrium current-induced state of a quasi-one-dimensional superconducting channel. The most interesting phenomenon here is the stepped I–V characteristic, explained by a process known as phase slip center activation. If the origin of such step-like ...
Added: October 13, 2026
Aladyshkin A. Y., Фраерман А. А., Н. Новгород: Национальный исследовательский Нижегородский государственный университет им. Н.И. Лобачевского, 2024.
В книге затронут широкий круг вопросов физики ограниченных твёрдых тел. Рассмотрено взаимодействие электромагнитного излучения рентгеновского диапазона, «тепловых» нейтронов и электронов с поверхностью твёрдого тела и многослойными структурами. Излагаются основы теории электронных состояний в полуограниченных твёрдых телах и применение метода туннельной спектроскопии для экспериментального изучения этих состояний. Возникновение поверхностной (прикраевой) сверхпроводимости на границах раздела рассматривается как ...
Added: February 1, 2024
N.I. Fedotov, Maizlakh A. A., V.V. Pavlovskiy et al., Surfaces and Interfaces 2022 Vol. 31 Article 102015
Bi2Te3 is a material with high efficiency of thermoelectric energy conversion. Recently, it was also recognized as a topological insulator, and is often used as the basis for creation of other types of topological matter. Pulsed laser deposition (PLD) is widely considered as a simple method for growing of multicomponent films, but not as a ...
Added: January 31, 2024
Aladyshkin A. Y., Journal of Physical Chemistry C 2023 Vol. 127 No. 27 P. 13295–13301
Local structural and electronic properties of thin Pb(111) films grown on Si(111)7x7 surface are experimentally studied by means of low-temperature scanning tunneling microscopy and spectroscopy (STM/STS). It is shown that the visible height h of the monatomic step on Pb(111) surface demonstrates oscillatory dependence on bias voltage U. The period of these oscillations coincides with the period ...
Added: July 13, 2023