Search results for "Nonlinear"
showing 10 items of 3684 documents
Critical wetting in the square Ising model with a boundary field
1990
The Ising square lattice with nearest-neighbor exchangeJ>0 and a free surface at which a boundary magnetic fieldH1 acts has a second-order wetting transition. We study the surface excess magnetization and the susceptibility ofL×M lattices by Monte Carlo simulation and probe the critical behavior of this wetting transition, applying finite-size scaling methods. For the cases studied, the results are not consistent with the presumably exactly known values of the critical exponents, because the asymptotic critical region has not yet been reached. Implication of our results for critical wetting in three dimensions and for the application of the present model to adsorbed wetting layers at surfac…
Nonlinear Analysis of Phase-locked Loop-Based Circuits
2013
Main problems of simulation and mathematical modeling of high-frequency signals for analog Costas loop and for analog phase-locked loop (PLL) are considered. Two approachers which allow to solve these problems are considered. In the first approach, nonlinear models of classical PLL and classical Costas loop are considered. In the second approach, engineering solutions for this problems are described. Nonlinear differential equations are derived for both approaches.
Analytical methods for computation of phase-detector characteristics and PLL design
2011
An effective analytical methods for computation of phase detector characteristics are suggested. For high-frequency oscillators new classes of such characteristics are described. Approaches to a rigorous nonlinear analysis of PLL are discussed.
Nonlinear analysis of phase-locked loop
2010
Abstract New method for the rigorous mathematical nonlinear analysis of PLL systems is suggested. This method allows to calculate the characteristics of phase detectors and carry out a rigorous mathematical analysis of transient process and stability of the system.
Control of photoassociation of atomic Bose-Einstein condensates by laser field configuration
2016
In this work we show that it is to perform an efficient adiabatic passage in a basic quadratic-nonlinear quantum two-state system describing weakly bound molecule formation in atomic Bose-Einstein condensates through photoassociation by laser fields. An efficient adiabatic transfer is also possible if the third-order nonlinearities describing the atom-atom, atom-molecule, and molecule-molecule elastic scattering are taken into account. The transfer is achieved by choosing a proper detuning derived by solving the inverse problem.We also show that one can perform a stimulated Raman exact tracking in a quadratic-nonlinear quantum three-state system.The irreversible losses from the intermediate…
Electrical control of the nonlinear properties of plasmonic nanostructures
2020
This work brings nano-electronics and nano-photonics technologies together to create an electron- plasmon device whose linear and nonlinear optical properties are electrically controlled. Here, we present the first demonstration of nonlinear photoluminescence modulation by electrical means in an uncluttered configuration. To this purpose, plasmonic nanoantennas are interfaced with elec- trical connections inducing localized regions of electron accumulation and depletion and therefore affecting the optical response. Additionally, a complete analysis of the nonlinear photoluminescence in plasmonic nanowires is carried out. The delocalization and transport of nonlinearities provided by such st…
Designing time and frequency entanglement for generation of high-dimensional photon cluster states
2020
The development of quantum technologies for quantum information science demands the realization and precise control of complex (multipartite and high dimensional) entangled systems on practical and scalable platforms. Quantum frequency combs (QFCs) generated via spontaneous four-wave mixing in integrated microring resonators represent a powerful tool towards this goal. They enable the generation of complex photon states within a single spatial mode as well as their manipulation using standard fiber-based telecommunication components. Here, we review recent progress in the development of QFCs, with a focus on our results that highlight their importance for the realization of complex quantum …
Ultrafast Fault-Tolerant Long-Distance Quantum Communication with Static Linear Optics
2017
We present an in-depth analysis regarding the error resistance and optimization of our all-optical Bell measurement and ultrafast long-distance quantum communication scheme proposed in [arXiv:1503.06777]. In order to promote our previous proposal from loss- to fault-tolerance, we introduce a general and compact formalism that can also be applied to other related schemes (including non-all-optical ones such as [PRL 112, 250501]). With the help of this new representation we show that our communication protocol does not only counteract the inevitable photon loss during channel transmission, but is also able to resist common experimental errors such as Pauli-type errors (bit- and phase-flips) a…
Modeling spectral correlations of photon-pairs generated in liquid-filled photonic crystal fiber
2020
The generation of photon-pairs with controllable spectral correlations is crucial in quantum photonics. Here we present the design of a photonic crystal fiber to generate widely-spaced four-wave mixing bands with spectral correlations that can be tuned through the thermo-optic effect after being infiltrated with heavy water. We present a theoretical study of the purity of the signal (idler) photon generated as a function of temperature, pump spectral linewidth and the length of the fiber. 511-6/18-8876 CIIC155/2019 APN-624 TEC2016- 76664-C2-1-R PROMETEO/2019/048
Scanning optical microscopy modeling in nanoplasmonics
2012
International audience; One of the main purposes of nanoplasmonics is the miniaturization of optical and electro-optical components that could be integrable in coplanar geometry. In this context, we propose a numerical model of a polarized scanning optical microscope able to faithfully reproduce both photon luminescence and temperature distribution images associated with complex plasmonic structures. The images are computed, pixel by pixel, through a complete self-consistent scheme based on the Green dyadic functions (GDF) formalism. The basic principle consists in the numerical implementation of a realistic three-dimensional light beam acting as a virtual light tip able to probe the volume…