Search results for "Sip"

New rotational levels in $^{186}$Re nucleus

2020

International audience; Excited levels of 186 Re have been studied using results of the single γ -ray spectra measurements following the thermal neutron capture reaction. Energies and intensities of more than 500 γ -transitions have been obtained with the high-resolution crystal diffraction spectrometer GAMS5 of ILL. Most of the obtained intense γ -transitions have been placed in the 186 Re level scheme. A number of new levels, as well as the depopulation for levels observed earlier in the 187 Re (p,d)186 Re reaction measurements have been proposed. Structure of 186 Re levels is interpreted in terms of two-quasiparticle plus rotor coupling model and compared with that of the neighbouring do…

Experimental demonstration of hyperbolic patterns.

2008

We give experimental evidence of hyperbolic patterns in a nonlinear optical resonator. Such transverse patterns are a new kind of 2D dissipative structures, characterized by a distribution of the active modes along hyperbolas in the transverse wave-vector domain, in contrast with the usual (elliptic) patterns where the active modes distribute along rings. The hyperbolic character is realized by manipulating diffraction inside the optical resonator with cylindrical lenses. We also investigate theoretically hyperbolic patterns in corresponding Swift-Hohenberg models.

2D shape relaxation dynamics in amphiphile monolayers

2007

The shape relaxation dynamics of the droplets in amphiphile monolayers is studied in Darcy approximation. It is shown by numerical experiments that relaxation from the highly extended dumbbell configurations can be described by simple physical model according to which the dissipation is concentrated on circular tips. By numerical simulation it is illustrated that longrange dipolar interactions lead to the stabilization of the shape relaxation process with respect to the formation of a narrow neck causing the rupture of the droplet when dipolar forces are absent. Effect of the dipolar forces on the shape-relaxation process can be accounted by the slope of the relaxation curve at small deviat…

Microscopic theory for the light-induced anomalous Hall effect in graphene

2019

We employ a quantum Liouville equation with relaxation to model the recently observed anomalous Hall effect in graphene irradiated by an ultrafast pulse of circularly polarized light. In the weak-field regime, we demonstrate that the Hall effect originates from an asymmetric population of photocarriers in the Dirac bands. By contrast, in the strong-field regime, the system is driven into a non-equilibrium steady state that is well-described by topologically non-trivial Floquet-Bloch bands. Here, the anomalous Hall current originates from the combination of a population imbalance in these dressed bands together with a smaller anomalous velocity contribution arising from their Berry curvature…

Existence of fixed points for the sum of two operators

2010

The purpose of this paper is to study the existence of fixed points for the sum of two nonlinear operators in the framework of real Banach spaces. Later on, we give some examples of applications of this type of results (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Design of innovative friction damper devices for earthquake-resilient RC frames with Hybrid Steel-Trussed Concrete Beams

2021

This thesis focuses on the design of innovative friction damper devices for earthquake-resilient Reinforced Concrete (RC) frames realized with Hybrid Steel-Trussed Concrete Beams (HSTCBs). These devices fall within the framework of the recently-proposed low-damage design strategy for structures built in earthquake-prone areas, on the basis of which the structures are designed to experience negligible damage when subjected to seismic events. The comprehensive solution proposed aims at introducing a feasible option for building earthquake-resilient RC Moment Resisting Frames (MRFs), having been proposed very few solutions for this structural scheme so far. Innovative solutions are proposed fo…

DISSIPATIVE DYNAMICS OF MULTI-STATE QUANTUM SYSTEMS IN THE WEAK TO STRONG COUPLING REGIME

In this thesis the dissipative dynamics of bistable quantum systems is studied within the path integral approach. The path integral representation of the propagator for quantum states and density matrices of discrete variable systems is described along with the Feynman-Vernon influence functional. The main approximations to the FV influence for the spin-boson model are introduced and applied to a bistable system beyond the two-level system approximation, the so-called double-doublet system. By the combined use of the Bloch-Redfield perturbative approach and of the path integral techniques, a phase diagram showing the various dynamical and dissipative regimes of the double-doublet system is …

Periodic and quasi-periodic orbits of the dissipative standard map

2011

We present analytical and numerical investigations of the dynamics of the dissipative standard map. We first study the existence of periodic orbits by using a constructive version of the implicit function theorem; then, we introduce a parametric representation, which provides the interval of the drift parameter ensuring the existence of a periodic orbit with a given period. The determination of quasi--periodic attractors is efficiently obtained using the parametric representation combined with a Newton's procedure, aimed to reduce the error of the approximate solution provided by the parametric representation. These methods allow us to relate the drift parameter of the periodic orbits to th…

Dissipative rogue wave generation in multiple-pulsing mode-locked fiber laser

2013

Following the first experimental observation of a new mechanism leading to optical rogue wave (RW) formation briefly reported in Lecaplain et al (2012 Phys. Rev. Lett. 108 233901), we provide an extensive study of the experimental conditions under which these RWs can be detected. RWs originate from the nonlinear interactions of bunched chaotic pulses that propagate in a fiber laser cavity, and manifest as rare events of high optical intensity. The crucial influence of the electrical detection bandwidth is illustrated. We also clarify the observation of RWs with respect to other pulsating regimes, such as Q-switching instability, that also lead to L-shaped probability distribution functions.…

Contrôle quantique adiabatique : technique de passage adiabatique parallèle et systèmes dissipatifs

2011

The first part of this thesis is devoted to the theoretical analysis of adiabatic processes allowing the transfer of population from an initial state to a target state of a quantum system. The strategy of parallel adiabatic passage, in which the coupling parameters are specifically designed to optimize the adiabatic passage corresponding to parallel eigenvalues at all times, allows one to combine the energetically efficiency of pi-pulse and related strategies with the robustness of standard adiabaticpassage. The second part of this thesis concerns the effects of the dissipation in adiabatic passage. The non-adiabatic transition probability formula of a two state system with dissipation is e…