81 results match your criteria: "and Moscow Institute of Physics and Technology[Affiliation]"

The theoretical background of the nonperturbative method of spectral response to stochastic processes (SRSP) for measuring the nonreciprocal interparticle effective interactions in strongly coupled underdamped systems is described. Analytical expressions for vibrational spectral density of confined Brownian particles with a nonreciprocal effective interaction are presented. The changes in the vibrational spectral density with varying different parameters of the system (nonreciprocity, viscosity, ratios of particle sizes, and intensities of random processes acting on each particle) are discussed using the example of a pair of nonidentical particles in a harmonic trap.

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Local versus translationally invariant slowest operators in quantum Ising spin chains.

Phys Rev E

August 2023

Skolkovo Institute of Science and Technology, Bolshoy Boulevard 30, bld. 1, Moscow 121205, Russia and Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny 141700, Russia.

In this paper we study one-dimensional quantum Ising spin chains in an external magnetic field close to an integrable point. We concentrate on the dynamics of the slowest operator that plays a key role at the final period of thermalization. We introduce two independent definitions of the slowest operator: local and translationally invariant ones.

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We study the acceleration of the Local Polynomial Interpolation-based Gradient Descent method (LPI-GD) recently proposed for the approximate solution of empirical risk minimization problems (ERM). We focus on loss functions that are strongly convex and smooth with condition number . We additionally assume the loss function is -Hölder continuous with respect to the data.

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Overcoming the Diffraction Limit on the Size of Dielectric Resonators Using an Amplifying Medium.

Phys Rev Lett

September 2022

Dukhov Research Institute of Automatics, 22 Sushchevskaya, Moscow 127055, Russia and Moscow Institute of Physics and Technology, 9 Institutskiy pereulok, Moscow 141700, Russia.

Existing methods for the creation of subwavelength resonators use either structures with negative permittivity, by exploiting subwavelength plasmonic resonances, or dielectric structures with a high refractive index, which reduce the wavelength. Here, we provide an alternative to these two methods based on a modification of the modes of dielectric resonators by means of an active medium. On the example of the dielectric active layer of size substantially smaller than a half-wavelength of light, we demonstrate that there is a gain at exceeding of which the change in phase due to the reflection at the layer boundaries compensates the change in phase due to propagation over the layer.

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One-component plasma of a million particles via angular-averaged Ewald potential: A Monte Carlo study.

Phys Rev E

July 2022

Joint Institute for High Temperatures, Izhorskaya 13 Bldg 2, Moscow 125412, Russia and Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region, 141701, Russia.

In this work we derive a correct expression for the one-component plasma (OCP) energy via the angular-averaged Ewald potential (AAEP). Unlike Yakub and Ronchi [J. Low Temp.

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Continuous Kubo-Greenwood formula: Theory and numerical implementation.

Phys Rev E

March 2022

Joint Institute for High Temperatures, Izhorskaya 13 Building 2, Moscow 125412, Russia and Moscow Institute of Physics and Technology, Institutskiy Pereulok 9, Dolgoprudny, Moscow Region 141700, Russia.

In this paper, we present the so-called continuous Kubo-Greenwood formula intended for the numerical calculation of the dynamic Onsager coefficients and, in particular, the real part of dynamic electrical conductivity. In contrast to the usual Kubo-Greenwood formula, which contains the summation over a discrete set of transitions between electron energy levels, the continuous one is formulated as an integral over the whole energy range. This integral includes the continuous functions: the smoothed squares of matrix elements, D(ɛ,ɛ+ℏω), the densities of state, g(ɛ)g(ɛ+ℏω), and the difference of the Fermi weights, [f(ɛ)-f(ɛ+ℏω)]/(ℏω).

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Electrochemical operational principles and analytical performance of Pd-based amperometric nanobiosensors.

Analyst

July 2021

Institute of Problems of Chemical Physics RAS, 1 Ac. Semenov avenue, Chernogolovka, 142432, Moscow region, Russia. and Moscow Institute of Physics and Technology, 9 Institutskiy per., Dolgoprudny, 141700, Moscow region, Russia.

Palladium nanoparticles (Pd-NPs) have been approved as an effective catalyst for hydrogen peroxide decomposition which is released during specific enzymatic reactions. However, the general operational principles and electrochemical performance of Pd-NPs-based nanobiosensors have been poorly exploited. Here, the electrochemical behavior of oxidase-associated peroxide oxidation co-catalysis of the modelled microanalytical system based on screen-printed electrodes modified by electroplated Pd-NPs as an electrocatalyst, glucose oxidase (GOx) or alcohol oxidase (AOx) as a bioreceptor and the ionomer Nafion as a polymeric binding agent was studied in detail.

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We discuss the possibility of using mixed-valence (MV) dimers comprising paramagnetic metal ions as molecular cells for quantum cellular automata (QCA). Thus, we propose to combine the underlying idea behind the functionality of QCA of using the charge distributions to encode binary information with the additional functional options provided by the spin degrees of freedom. The multifunctional ("smart") cell is supposed to consist of multielectron MV dn-dn+1-type (1 ≤ n ≤ 8) dimers of transition metal ions as building blocks for composing bi-dimeric square planar cells for QCA.

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The lack of high throughput screening (HTS) techniques for small molecules that stabilize DNA iMs limits their development as perspective drug candidates. Here we showed that fluorescence monitoring for probing the effects of ligands on the iM stability using the FAM-BHQ1 pair provides incorrect results due to additional dye-related interactions. We developed an alternative system with fluorescent phenoxazine pseudonucleotides in loops that do not alter iM unfolding.

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Designing sensors for toxic compounds such as mercury salts in aqueous solutions still remains one of the most pressing tasks of modern chemical research, since many existing systems do not show enough sensitivity and/or response. In this regard, the opportunities offered by supramolecular approaches can be used to improve both these characteristics by creating a new self-organized smart system. Herein, we show that barium cations, that according to the data of X-ray standing waves do not bind directly to the ionophore molecules in the monolayers at the air/water interface, could be used to efficiently preorganize such molecules to achieve supramolecular architecture.

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Article Synopsis
  • G-quadruplexes (G4) are unique DNA structures that are being explored as potential targets for therapies against cancer, viruses, and bacteria.
  • Researchers developed a new type of ligand using a phenoxazine scaffold that stabilizes G4, optimizing the design through computer modeling.
  • The synthesized ligands showed improved thermal stability of G4 by raising its melting temperature significantly while selectively targeting G4 over traditional DNA structures, indicating their potential for further biological research.
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Insights into the regularity of the formation of 2D 3d transition metal monocarbides.

Nanoscale

July 2020

National University of Science and Technology MISiS, 4 Leninskiy prospekt, Moscow, 119049, Russian Federation. and Moscow Institute of Physics and Technology, Institute lane 9, Dolgoprudny, Moscow Region, Russian Federation.

Recently, several theoretical predictions have been made about 2D planar FeC, CoC, NiC, and CuC, while their bulk phases still remain unknown. Here, we present a generalization of the 2D family of 3d transition metal monocarbides (TMC) by searching for their stable configurations with DFT methods and an evolutionary algorithm. It is found that in the TMC row (TM = Sc-Cu) the tendency of 3D rocksalt phase formation is monotonously interchanged with 2D phase appearance, namely, planar orthorhombic TMC characterized by carbon dimers inside metal hexagons.

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Electrochemical aspects of Bi electrocrystallization from a bath containing bismuth nitrate in a mixture of ethylene glycol and water are addressed. Bismuth nanowires with diameters of 50-120 nm and a length of up to a few dozen microns were prepared by electrodeposition into the pores of anodic aluminium oxide templates. Crystal structure and morphology of electrodeposited materials were characterized using electron microscopy, selected area electron diffraction, and X-ray diffraction analysis.

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Correction for 'Materials space of solid-state electrolytes: unraveling chemical composition-structure-ionic conductivity relationships in garnet-type metal oxides using cheminformatics virtual screening approaches' by Natalia Kireeva et al., Phys. Chem.

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Stability and gas sensing properties of TaXM (X = Pd, Pt; M = S, Se) nanoribbons: a first-principles investigation.

Phys Chem Chem Phys

July 2020

National University of Science and Technology MISiS, 4 Leninskiy prospekt, Moscow, 119049, Russian Federation. and Moscow Institute of Physics and Technology (State University), 9 Institutskiy per., Dolgoprudny, Moscow Region, 141701, Russian Federation.

One dimensional Ta2(Pd/Pt)3(S/Se)8 nanoribbons (TPS-NR) are considered as a promising material in nanoelectronics due to their intrinsic semiconducting electronic properties. In this article, we study the stability of TPS-NR by considering their oxidation process. Our calculations showed that the Ta2(Pd/Pt)3Se8 nanoribbons are more environmentally stable than Ta2(Pd/Pt)3S8-NR.

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We present a molecular dynamics simulation study of the phase diagram and melting scenarios of two-dimensional Hertzian spheres with exponent 7/2. We have found multiple re-entrant melting of a single crystal with a triangular lattice in a wide range of densities from 0.5 to 10.

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The work presented in this paper shows with the help of two-dimensional hydrodynamic simulations that intense heavy-ion beams are a very efficient tool to induce high energy density (HED) states in solid matter. These simulations have been carried out using a computer code BIG2 that is based on a Godunov-type numerical algorithm. This code includes ion beam energy deposition using the cold stopping model, which is a valid approximation for the temperature range accessed in these simulations.

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Manifestation of specific features of T-exciton migration in magnetic field effects on TT-annihilation in molecular crystals: Analysis of low-field resonances.

J Chem Phys

December 2019

Institute of Chemical Physics, Russian Academy of Sciences, GSP-1, Kosygin St. 4, Moscow 119991, Russian Federation and Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny 141700, Moscow Region, Russian Federation.

The manifestation of specific features of T-exciton migration in the shape of low field resonances (LFRs) in the magnetic field effects on the TT-annihilation in molecular crystals is studied in detail. The LFRs are shown to be caused by avoided crossing of spin-levels of T-excitons in magnetic fields nearly parallel to the axis of the zero field splitting interaction tensor. Simple and accurate formulas for the shape of the LFR-line are derived within the hopping model of T-exciton migration.

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The emergence of ferroelectricity in nanometer-thick films of doped hafnium oxide (HfO) makes this material a promising candidate for use in Si-compatible non-volatile memory devices. The switchable polarization of ferroelectric HfO controls functional properties of these devices through the electric potential distribution across the capacitor. The experimental characterization of the local electric potential at the nanoscale has not so far been realized in practice.

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Anomalous behavior and structure of a liquid of particles interacting through the harmonic-repulsive pair potential near the crystallization transition.

Soft Matter

November 2019

Institute for High Pressure Physics, Russian Academy of Sciences, 108840, Moscow (Troitsk), Russia and Ural Federal University, 19 Mira str., 620002, Ekaterinburg, Russia and Moscow Institute of Physics and Technology, Institutskiy per. 9, Dolgoprudny, Moscow Region 141700, Russia.

A characteristic property of many soft matter systems is an ultrasoft effective interaction between their structural units. This softness often leads to complex behavior. In particular, ultrasoft systems under pressure demonstrate polymorphism of complex crystal and quasicrystal structures.

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A novel candle light-style OLED with a record low colour temperature.

Chem Commun (Camb)

November 2019

N. D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, 119991 Moscow, Russia. and Nanotechnology Education and Research Center, South Ural State University, 454080 Chelyabinsk, Russia.

The possibility of using a single light-emitting layer consisting of newly synthesized fluorescent small organic molecules of D-A-π-A type incorporated into a conductive matrix together with an electron conductive Alq layer in order to form radiation in candle light-style OLEDs was shown for the first time. A record low color temperature of 1722 K OLED radiation was achieved, which is by 80 K lower than that of the best devices reported previously.

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A manganese(ii) phthalocyanine under water-oxidation reaction: new findings.

Dalton Trans

August 2019

Controlled Photobiosynthesis Laboratory, K.A. Timiryazev Institute of Plant Physiology, Russian Academy of Sciences, Botanicheskaya Street 35, Moscow 127276, Russia. and Bionanotechnology Laboratory, Institute of Molecular Biology and Biotechnology, Azerbaijan National Academy of Sciences, Matbuat Avenue 2a, Baku 1073, Azerbaijan and Institute of Basic Biological Problems, Russian Academy of Sciences, Pushchino, Moscow Region 142290, Russia and Department of Plant Physiology, Faculty of Biology, M.V. Lomonosov Moscow State University, Leninskie Gory 1-12, Moscow 119991, Russia and Moscow Institute of Physics and Technology, Institutsky lane 9, Dolgoprudny, Moscow Region 141700, Russia.

Phthalocyanines are a promising class of ligands for manganese because of their high binding affinity. This effect is suggested to be an important factor because phthalocyanines tightly bind manganese and stabilize it under moderate conditions. The strong donor power of phthalocyanine is also suggested as a critical factor to stabilize high-valent manganese phthalocyanine.

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Kinetics of singlet fission in organic semiconductors: Specific features of T-exciton migration effects.

J Chem Phys

July 2019

Institute of Chemical Physics, Russian Academy of Sciences, 119991, GSP-1, Kosygin St. 4, Moscow, Russian Federation and Moscow Institute of Physics and Technology, Institutsky Lane 9, Dolgoprudny 141700, Moscow Region, Russian Federation.

Kinetics of singlet fission (SF) in organic semiconductors, associated with spontaneous splitting of the excited singlet state (S) into a pair of triplet (T) excitons, is known to be strongly affected by geminate annihilation of generated TT-pairs. In this work, we analyze in detail the SF-kinetics within lattice-migration (hopping), diffusion-migration, and exponential-kinetics two-state models (TSMs), which allow us to accurately describe the effects of relative T-exciton migration in TT-pairs. In the proposed TSMs, the migration effects are treated within the approximation of kinetic coupling of two states: [TT]-state of interacting TT-pairs and [T + T]-state of freely migrating T-excitons.

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Semiclassical versus quantum-mechanical vibronic approach in the analysis of the functional characteristics of molecular quantum cellular automata.

Phys Chem Chem Phys

August 2019

Department of Chemistry, Ben-Gurion University of the Negev, 84105 Beer-Sheva, Israel. and Department of Chemical Sciences, Ariel University, 40700 Ariel, Israel.

In the context of the decisive role that vibronic interactions play in the functioning of molecular quantum cellular automata, in this article we give a comparative analysis of the two alternative vibronic approaches to the evaluation of the key functional characteristics of molecular cells. Semiclassical Born-Oppenheimer approximation and quantum mechanical evaluations of the vibronic energy pattern, electronic density distributions and cell-cell response function are performed for two-electron square-planar mixed valence molecular cells subjected to the action of a molecular driver. Special emphasis is put on the description of the cell-cell response function, which describes strong non-linearity as a prerequisite for the effective action of quantum cellular automata.

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Enhancement of the Raman Effect by Infrared Pumping.

Phys Rev Lett

April 2019

Department of Physics, Queens College of the City University of New York, Flushing, New York 11367, USA and The Graduate Center of the City University of New York, New York, New York 10016, USA.

We propose a method for increasing Raman scattering from an ensemble of molecules by up to 4 orders of magnitude. Our method requires an additional coherent source of IR radiation with the half-frequency of the Stokes shift. This radiation excites the molecule electronic subsystem that in turn, via Fröhlich coupling, parametrically excites nuclear oscillations at a resonant frequency.

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