11 results match your criteria: "Institute for Spectroscopy RAS[Affiliation]"
Biosensors (Basel)
December 2022
Department of Advanced Photonics and Sensorics, Lebedev Physical Institute RAS, Troitsk Branch, Fizicheskaya Str. 11, 108840 Moscow, Troitsk, Russia.
The most relevant technique for portable (on-chip) sensors is Surface Enhanced Raman Scattering (SERS). This strategy crashes in the case of large (biorelevant) molecules and nano-objects, whose SERS spectra are irreproducible for "homeopathic" concentrations. We suggested solving this problem by SERS-mapping.
View Article and Find Full Text PDFMembranes (Basel)
November 2022
Laboratory of Advanced Materials Physics, Moscow Pedagogical State University, 119991 Moscow, Russia.
The investigation of the mechanical properties of polymer track-etched membranes (TMs) has attracted significant attention in connection with the extended region of their possible applications. In the present work, the mechanical stress fields around the pores of an elongated polyethylene terephthalate TM and around the 0.3 mm holes in model polymer specimens were studied in polarized light and with the finite element method.
View Article and Find Full Text PDFPhys Rev Lett
February 2022
Institute for Spectroscopy RAS, 5 Fizicheskaya, Troitsk 142190, Russia; Moscow Institute of Electronics and Mathematics, National Research University Higher School of Economics, 101000 Moscow, Russia; Hybrid Photonics Laboratory, Skolkovo Institute of Science and Technology, Territory of Innovation Center Skolkovo, Bolshoy Boulevard 30, building 1, 121205 Moscow, Russia; and Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow 127055, Russia.
In this Letter, we give an analytical quantum description of a nonequilibrium polariton Bose-Einstein condensate (BEC) based on the solution of the master equation for the full polariton density matrix in the limit of fast thermalization. We find the density matrix of a nonequilibrium BEC, that takes into account quantum correlations between all polariton states. We show that the formation of BEC is accompanied by the build-up of cross-correlations between the ground state and the excited states reaching their highest values at the condensation threshold.
View Article and Find Full Text PDFNature
December 2021
Center for Photonics and Quantum Materials, Skolkovo Institute of Science and Technology, Moscow, Russia.
Nature
September 2021
Center for Photonics and Quantum Materials, Skolkovo Institute of Science and Technology, Moscow, Russia.
The recent progress in nanotechnology and single-molecule spectroscopy paves the way for emergent cost-effective organic quantum optical technologies with potential applications in useful devices operating at ambient conditions. We harness a π-conjugated ladder-type polymer strongly coupled to a microcavity forming hybrid light-matter states, so-called exciton-polaritons, to create exciton-polariton condensates with quantum fluid properties. Obeying Bose statistics, exciton-polaritons exhibit an extreme nonlinearity when undergoing bosonic stimulation, which we have managed to trigger at the single-photon level, thereby providing an efficient way for all-optical ultrafast control over the macroscopic condensate wavefunction.
View Article and Find Full Text PDFPhys Rev Lett
December 2018
Institute for Spectroscopy RAS, 142190 Troitsk, Moscow, Russia.
We propose a way to increase the lifetime of two-dimensional direct excitons and show the possibility to observe their macroscopically coherent state at temperatures much higher than that of indirect exciton condensation. For a single GaAs quantum well embedded in photonic layered heterostructures with subwavelength period, we predict the exciton radiative decay to be strongly suppressed. Quantum hydrodynamics joined with the Bogoliubov approach are used to study the Berezinskii-Kosterlitz-Thouless crossover in a finite exciton system with intermediate densities.
View Article and Find Full Text PDFSci Rep
January 2018
Moscow Institute of Physics and Technology (State University), Institutskiy pereulok str. 9, Dolgoprudny, Moscow region, 141701, Russia.
Targeting micrometer sized metal droplets with near-infrared sub-picosecond laser pulses generates intense stress-confined acoustic waves within the droplet. Spherical focusing amplifies their pressures. The rarefaction wave nucleates cavitation at the center of the droplet, which explosively expands with a repeatable fragmentation scenario resulting into high-speed jetting.
View Article and Find Full Text PDFPhys Chem Chem Phys
March 2017
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA.
We employ X-ray absorption near-edge spectroscopy at the boron K-edge and the phosphorus L-edge to study the structural properties of cubic boron phosphide (c-BP) samples. The X-ray absorption spectra are modeled from first-principles within the density functional theory framework using the excited electron core-hole (XCH) approach. A simple structural model of a perfect c-BP crystal accurately reproduces the P L-edge, however it fails to describe the broad and gradual onset of the B K-edge.
View Article and Find Full Text PDFPhys Rev Lett
October 2015
Institute for Spectroscopy RAS, 142190 Troitsk, Moscow, Russia.
We theoretically analyze exciton-photon oscillatory dynamics within a homogenous polariton gas in the presence of energy detuning between the cavity and quantum well modes. Whereas pure Rabi oscillations consist of the particle exchange between the photon and exciton states in the polariton system without any oscillations of the phases of the two subcondensates, we demonstrate that any nonzero detuning results in oscillations of the relative phase of the photon and exciton macroscopic wave functions. Different initial conditions reveal a variety of behaviors of the relative phase between the two condensates, and a crossover from Rabi-like to Josephson-like oscillations is predicted.
View Article and Find Full Text PDFJ Chem Phys
October 2014
Institute for spectroscopy RAS, Troitsk, 142190 Moscow, Russia.
It has been recently found [Gh. Galland, Y. Ghosh, A.
View Article and Find Full Text PDFPhys Rev Lett
November 2006
Institute for Spectroscopy RAS, Troitsk, Moscow Region, 142190 Russia.
An experimental method is proposed for the creation of plasma optical waveguides at low electron densities. The method consists of creating a hollow neutral-hydrogen channel by means of fast local heating of a hydrogen volume by a needlelike electron beam, followed by laser ionization of the hydrogen to provide the plasma waveguide. Results of numerical simulations are presented which show that guiding with an axial electron density in the range of 10(17) cm-3 can be achieved with a matched spot size of 30 microm.
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