Discrete light localization in one dimensional nonlinear lattices with arbitrary non locality

We model discrete spatial solitons in a periodic nonlinear medium encompassing any degree of transverse non locality. Making a convenient reference to a widely used material -nematic liquid crystals-, we derive a new form of the discrete nonlinear Schrodinger equation and find a novel family of discrete solitons. Such self-localized solutions in optical lattices can exist with an arbitrary degree of imprinted chirp and a have breathing character. We verify numerically that both local and non local discrete light propagation and solitons can be observed in liquid crystalline arrays.Comment: Extended version with 6 pages and 4 Figures, to appear in Phys. Rev.

Nonlinearly-enhanced energy transport in many dimensional quantum chaos

By employing a nonlinear quantum kicked rotor model, we investigate the transport of energy in multidimensional quantum chaos. Parallel numerical simulations and analytic theory demonstrate that the interplay between nonlinearity and Anderson localization establishes a perfectly classical correspondence in the system, neglecting any quantum time reversal. The resulting dynamics exhibits a nonlinearly-induced, enhanced transport of energy through soliton wave particles.Comment: 4 pages, 3 figures, submitte

Time-reversal focusing of an expanding soliton gas in disordered replicas

We investigate the properties of time reversibility of a soliton gas, originating from a dispersive regularization of a shock wave, as it propagates in a strongly disordered environment. An original approach combining information measures and spin glass theory shows that time reversal focusing occurs for different replicas of the disorder in forward and backward propagation, provided the disorder varies on a length scale much shorter than the width of the soliton constituents. The analysis is performed by starting from a new class of reflectionless potentials, which describe the most general form of an expanding soliton gas of the defocusing nonlinear Schroedinger equation.Comment: 7 Pages, 6 Figure

Bistability and instability of dark-antidark solitons in the cubic-quintic nonlinear Schroedinger equation

We characterize the full family of soliton solutions sitting over a background plane wave and ruled by the cubic-quintic nonlinear Schroedinger equation in the regime where a quintic focusing term represents a saturation of the cubic defocusing nonlinearity. We discuss existence and properties of solitons in terms of catastrophe theory and fully characterize bistability and instabilities of the dark-antidark pairs, revealing new mechanisms of decay of antidark solitons.Comment: 8 pages, 10 figures, accepted in PR

Modelling of the dynamic interaction between a reacting spray and an acoustic field in a turbulent combustor

The work presented in this paper is a first attempt at tracing both the vaporization droplet his-tory and the momentum exchange between the liquid and gas phase, in a reacting flow field exposed to acoustic propagation waves. The liquid phase is tracked with a Lagrangian ap-proach, while the carrier gas phase is modelled in an Eulerian framework, based in a two-way coupling interaction, under the main assumptions of dilute regime and infinite thermal con-ductivity. Acoustic propagating waves will eventually affect the combustion dynamic due to oscillating heat released by the flame. Aim of this work is to assess a strategy to estimate the effect of an oscillating gas velocity field on: droplet displacement, redistribution of the char-acteristic droplet diameters, changes in the evaporation rate. Assuming the hypothesis of di-lute regime as valid, the study is carried out by means of a non-dimensional number charac-terization

Nonradiating Photonics with Resonant Dielectric Nanostructures

Nonradiating sources of energy have traditionally been studied in quantum mechanics and astrophysics, while receiving a very little attention in the photonics community. This situation has changed recently due to a number of pioneering theoretical studies and remarkable experimental demonstrations of the exotic states of light in dielectric resonant photonic structures and metasurfaces, with the possibility to localize efficiently the electromagnetic fields of high intensities within small volumes of matter. These recent advances underpin novel concepts in nanophotonics, and provide a promising pathway to overcome the problem of losses usually associated with metals and plasmonic materials for the efficient control of the light-matter interaction at the nanoscale. This review paper provides the general background and several snapshots of the recent results in this young yet prominent research field, focusing on two types of nonradiating states of light that both have been recently at the center of many studies in all-dielectric resonant meta-optics and metasurfaces: optical {\em anapoles} and photonic {\em bound states in the continuum}. We discuss a brief history of these states in optics, their underlying physics and manifestations, and also emphasize their differences and similarities. We also review some applications of such novel photonic states in both linear and nonlinear optics for the nanoscale field enhancement, a design of novel dielectric structures with high-$Q$ resonances, nonlinear wave mixing and enhanced harmonic generation, as well as advanced concepts for lasing and optical neural networks.Comment: 22 pages, 9 figures, review articl