A Langevin analysis of fundamental noise limits in Coherent Anti-Stokes Raman Spectroscopy

We use a Langevin approach to analyze the quantum noise in Coherent Anti-Stokes Raman Spectroscopy (CARS) in several experimental scenarios: with continuous wave input fields acting simultaneously and with fast sequential pulsed lasers where one field scatters off the coherence generated by other fields; and for interactions within a cavity and in free space. In all the cases, the signal as well as the quantum noise due to spontaneous decay and decoherence in the medium are shown to be described by the same general expression. Our theory in particular shows that for short interaction times, the medium noise is not important and the efficiency is limited only by the intrinsic quantum nature of the photon. We obtain fully analytic results \emph{without} making an adiabatic approximation, the fluctuations of the medium and the fields are self solved consistently.Comment: 12 pages, 1 figur

Quantal Brownian Motion - Dephasing and Dissipation

We analyze quantal Brownian motion in $d$ dimensions using the unified model for diffusion localization and dissipation, and Feynman-Vernon formalism. At high temperatures the propagator possess a Markovian property and we can write down an equivalent Master equation. Unlike the case of the Zwanzig-Caldeira-Leggett model, genuine quantum mechanical effects manifest themselves due to the disordered nature of the environment. Using Wigner picture of the dynamics we distinguish between two different mechanisms for destruction of coherence. The analysis of dephasing is extended to the low temperature regime by using a semiclassical strategy. Various results are derived for ballistic, chaotic, diffusive, both ergodic and non-ergodic motion. We also analyze loss of coherence at the limit of zero temperature and clarify the limitations of the semiclassical approach. The condition for having coherent effect due to scattering by low-frequency fluctuations is also pointed out. It is interesting that the dephasing rate can be either larger or smaller than the dissipation rate, depending on the physical circumstances.Comment: LaTex, 23 pages, 4 figures, published vesio

On adaptive estimation using the sup-norm losses

We consider the problem of recovering smooth functions from noisy data using the supnorm as the quality criterion Starting with a natural projection estimator we show a datadriven procedure to be adaptive asymptotically minima

The Problem of Scheduling for the Linear Section of a Single-Track Railway with Independent Edges Orientations

The paper is devoted to the problem of scheduling for the linear section of a single-track railway: how to organize the ow in both directions in the most efficient way. In this paper, the authors propose an algorithm for scheduling with independent edges orientations, examine the properties of this algorithm and perform the computational experiments

Entanglement measurement of the quadrature components without the homodyne detection in the spatially multi-mode far-field

We consider the measuring procedure that in principle allows to avoid the homodyne detection for the simultaneous selection of both quadrature components in the far-field. The scheme is based on the use of the coherent sources of the non-classical light. The possibilities of the procedure are illustrated on the basis of the use of pixellised sources, where the phase-locked sub-Poissonian lasers or the degenerate optical parametric oscillator generating above threshold are chosen as the pixels. The theory of the pixellised source of the spatio-temporal squeezed light is elaborated as a part of this investigation.Comment: 11 pages, 5 figures, RevTeX4. Submitted to Phys. Rev.

Low temperature properties of a quantum particle coupled to dissipative environments

We study the dynamics of a quantum particle coupled to dissipative (ohmic) environments, such as an electron liquid. For some choices of couplings, the properties of the particle can be described in terms of an effective mass. A particular case is the three dimensional dirty electron liquid. In other environments, like the one described by the Caldeira-Leggett model, the effective mass diverges at low temperatures, and quantum effects are strongly suppressed. For interactions within this class, arbitrarily weak potentials lead to localized solutions. Particles bound to external potentials, or moving in closed orbits, can show a first order transition, between strongly and weakly localized regimes.Comment: 10 page

Physical Research of Carbon Nanomaterials in the Microwave Range

Techniques have been developed for measuring the electrophysical characteristics of carbon nanomaterials in the microwave range. The materials studied surpass all existing and used at present radio-absorbing materials in radio engineering in all electrophysical characteristics by several times. The results of an experimental study of the electrophysical characteristics of carbon nanomaterial samples make it possible to recommend them for practical use in the microwave range of wavelengths as lightweight composite materials for highly efficient electromagnetic shields, conducting and reflecting electromagnetic radiation structures in devices processing and transmitting microwave signals and other applications

О Модернизации Жилищного Законодательства И Построении Эффективных Финансовых Моделей Управления Многоквартирными Домами В Современной России

The article substantiates a set of proposals for amending housing legislation aimed at building effective financial models of various ways to manage apartment buildings in modern Russia. The implementation of the proposals will allow the creation of financially sustainable management organizations in the housing and utilities sector, who receive their remuneration in legal form and are interested in the results of their financial and economic activities. The study was carried out with the financial support of the Russian Foundation for Basic Research in the framework of the research project No. 18-010-00090 “Study of the financial and economic aspects of the activities of management companies in the housing and utilities sector and the development of proposals to improve their financial sustainability.”El artículo respalda un conjunto de propuestas para enmendar la legislación de vivienda con el objetivo de construir modelos financieros efectivos de varias maneras de administrar edificios de apartamentos en la Rusia moderna. La implementación de las propuestas permitirá la creación de organizaciones de gestión financieramente sostenibles en el sector de vivienda y servicios públicos, que reciben su remuneración en forma legal y están interesados en los resultados de sus actividades financieras y económicas. El estudio se realizó con el apoyo financiero de la Fundación Rusa para la Investigación Básica en el marco del proyecto de investigación Nº 18-010-00090 "Estudio de los aspectos financieros y económicos de las actividades de las empresas de gestión en el sector de la vivienda y los servicios públicos. y el desarrollo de propuestas para mejorar su sostenibilidad financiera ". В статье обосновывается комплекс предложений по изменению жилищного законодательства, направленного на построение эффективных финансовых моделей различных способов управления многоквартирными домами в современной России. Реализация предложений позволит создать финансово устойчивые управляющие организации сферы ЖКХ, получающие свое вознаграждение в легальной форме и заинтересованные в результатах своей финансово-хозяйственной деятельности.   Исследование выполнено при финансовой поддержке Российского фонда фундаментальных исследований в рамках научного проекта № 18-010-00090 «Исследование финансово-экономических аспектов деятельности управляющих компаний в сфере ЖКХ и разработка предложений по повышению их финансовой устойчивости»