Труды сотрудников ИВМ СО РАН

/ I. V. Krasnov // Laser Phys. - 2017. - Vol. 27, Is. 8. - Ст. 085501, DOI 10.1088/1555-6611/aa786c. - Cited References:26 . - ISSN 1054-660X. - ISSN 1555-6611РУБ Optics + Physics, Applied

Аннотация: A kinetic model of atom confinement in a bichromatic dark trap (BDT) is developed with the goal of describing its dissipative properties. The operating principle of the deep BDT is based on using the combination of multiple bichromatic cosine-Gaussian optical beams (CGBs) for creating high-potential barriers, which is described in our previous work (Krasnov 2016 Laser Phys. 26 105501). In the indicated work, particle motion in the BDT is described in terms of classical trajectories. In the present study, particle motion is analyzed by means of the Wigner function (phase-space distribution function (DF)), which allows one to properly take into account the quantum fluctuations of optical forces. Besides, we consider an improved scheme of the BDT, where CGBs create, apart from plane potential barriers, a narrow cooling layer. We find an asymptotic solution of the Fokker-Planck equation for the DF and show that the DF of particles deeply trapped in a BDT with a cooling layer is the Tsallis distribution with the effective temperature, which can be considerably lower than in a BDT without a cooling layer. Moreover, it can be adjusted by slightly changing the CGBs' radii. We also study the effect of particle escape from the trap due to the scattering of resonant photons and show that the particle lifetime in a BDT can exceed several tens of hours when it is limited by photon scattering.

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Держатели документа:
Russian Acad Sci, Inst Computat Modeling, Siberian Branch, FRC KSC, Krasnoyarsk 660036, Russia.

Доп.точки доступа:
Krasnov, I. V.

/ P. E. Cubillos [et al.] // Astrophys. J. - 2017. - Vol. 849, Is. 2, DOI 10.3847/1538-4357/aa9019 . - ISSN 0004-637X
Аннотация: The strong, nearly wavelength-independent absorption cross section of aerosols produces featureless exoplanet transmission spectra, limiting our ability to characterize their atmospheres. Here, we show that even in the presence of featureless spectra, we can still characterize certain atmospheric properties. Specifically, we constrain the upper and lower pressure boundaries of aerosol layers, and present plausible composition candidates. We study the case of the bloated Saturn-mass planet WASP-49 b, where near-infrared observations reveal a flat transmission spectrum between 0.7 and 1.0 ?m. First, we use a hydrodynamic upper-atmosphere code to estimate the pressure reached by the ionizing stellar high-energy photons at 10-8 bar, setting the upper pressure boundary where aerosols could exist. Then, we combine HELIOS and Pyrat Bay radiative-transfer models to constrain the temperature and photospheric pressure of atmospheric aerosols, in a Bayesian framework. For WASP-49 b, we constrain the transmission photosphere (hence, the aerosol deck boundaries) to pressures above 10-5 bar (100?solar metallicity), 10-4 bar (solar), and 10-3 bar (0.1?solar) as the lower boundary, and below 10-7 bar as the upper boundary. Lastly, we compare condensation curves of aerosol compounds with the planet's pressure-temperature profile to identify plausible condensates responsible for the absorption. Under these circumstances, we find these candidates: Na2S (at 100? solar metallicity); Cr and MnS (at solar and 0.1?solar); and forsterite, enstatite, and alabandite (at 0.1?solar). © 2017. The American Astronomical Society. All rights reserved.

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Держатели документа:
Space Research Institute, Austrian Academy of Sciences, Schmiedlstrasse 6, Graz, Austria
Federal Research Center Krasnoyarsk Science Center SB RAS, Institute of Computational Modelling, Krasnoyarsk, Russian Federation
Center for Space and Habitability, University of Bern, Sidlerstrasse 5, Bern, Switzerland
Institut fur Geophysik und Meteorologie, Universitat zu Koln, Albertus-Magnus-Platz, Koln, Germany
Max Planck Institute for Astronomy, Konigstuhl 17, Heidelberg, Germany
Department of Astrophysics, University of Vienna, Turkenschanzstrasse 17, Vienna, Austria
Geneva Observatory, University of Geneva, ch. de Maillettes 51, Versoix, Switzerland

Доп.точки доступа:
Cubillos, P. E.; Fossati, L.; Erkaev, N. V.; Malik, M.; Tokano, T.; Lendl, M.; Johnstone, C. P.; Lammer, H.; Wyttenbach, A.

/ V. I. Zakomirnyi [et al.] // Photonics Nanostruc. Fundam. Appl. - 2018. - Vol. 30. - P50-56, DOI 10.1016/j.photonics.2018.04.005 . - ISSN 1569-4410
Аннотация: We propose to utilize titanium nitride (TiN) as an alternative material for linear periodic chains (LPCs) of nanoparticles (NPs) which support surface plasmon polariton (SPP) propagation. Dispersion and transmission properties of LPCs have been examined within the framework of the dipole approximation for NPs with various shapes: spheres, prolate and oblate spheroids. It is shown that LPCs of TiN NPs support high-Q eigenmodes for an SPP attenuation that is comparable with LPCs from conventional plasmonic materials such as Au or Ag, with the advantage that the refractory properties and cheap fabrication of TiN nanostructures are more preferable in practical implementations compared to Au and Ag. We show that the SPP decay in TiN LPCs remains almost the same even at extremely high temperatures which is impossible to reach with conventional plasmonic materials. Finally, we show that the bandwidth of TiN LPCs from non-spherical particles can be tuned from the visible to the telecommunication wavelength range by switching the SPP polarization, which is an attractive feature for integrating these structures into modern photonic devices. © 2018 Elsevier B.V.

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Держатели документа:
Institute of Nanotechnology, Spectroscopy and Quantum Chemistry, Siberian Federal University, Krasnoyarsk, Russian Federation
School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden
The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
Institute of Computational Modeling, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation
Siberian State University of Science and Technology, Krasnoyarsk, Russian Federation
Kirensky Institute of Physics, Federal Research Center KSC SB RAS, Krasnoyarsk, Russian Federation

Доп.точки доступа:
Zakomirnyi, V. I.; Rasskazov, I. L.; Gerasimov, V. S.; Ershov, A. E.; Polyutov, S. P.; Karpov, S. V.; Agren, H.