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Related papers: Modulational instability in $\cal{PT}$-symmetric B…

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A combined theoretical/numerical/experimental program is outlined for extending the ILG approach to consider time lags, stochasticity and multiphysics couplings. Through this extension it is possible to discuss the interplay between…

Materials Science · Physics 2016-08-09 Elias C. Aifantis

We demonstrate the emergence of an entire flat band embedded in dispersive bands at the exceptional point of a PT symmetric photonic lattice. For this to occur, the gain and loss parameter effectively alters the size of the partial flat…

Optics · Physics 2017-07-12 Hamidreza Ramezani

We show that parity-time (PT) symmetric Bragg periodic structures, near the spontaneous PT - symmetry breaking point, can act as unidirectional invisible media. In this regime, the re flection from one end is diminished while it is enhanced…

In a previous paper (Leblond et al., 2011), we proposed a theoretical interpretation of the experimentally well known instability of coplanar crack propagation in mode I+III. The interpretation relied on a stability analysis based on…

Soft Condensed Matter · Physics 2019-03-27 Jean-Baptiste Leblond , Alain Karma , Laurent Ponson , Aditya Vasudevan

Aims: In the present work we investigate the nature of the magnetic Rayleigh-Taylor instability at a density interface permeated by an oblique, homogeneous magnetic field in an incompressible limit. Methods: Using the system of linearised…

Solar and Stellar Astrophysics · Physics 2020-02-19 E. Vickers , I. Ballai , R. Erdélyi

We develop a self-consistent method to study the optical response of metallic gratings with nonlinear media embedded within their subwavelength slits. An optical Kerr nonlinearity is considered. Due to the large E-fields associated with the…

Materials Science · Physics 2016-08-31 J. A. Porto , L. Martin-Moreno , F. J. Garcia-Vidal

We explore the optical properties of a Fabry-Perot resonator with an embedded Parity-Time (PT) symmetrical grating. This PT-symmetrical grating is non diffractive (transparent) when illuminated from one side and diffracting (Bragg…

Optics · Physics 2015-06-19 Mykola Kulishov , Bernand Kress , H. F. Jones

A one dimensional, parity-time (${\cal PT}$)-symmetric magnetic metamaterial comprising split-ring resonators having both gain and loss is investigated. In the linear regime, the transition from the exact to the broken ${\cal PT}$-phase is…

Pattern Formation and Solitons · Physics 2014-11-25 G. P. Tsironis , N. Lazarides

For the grating, which has depth of grooves as a small parameter, the dispersion equation of the Smith-Purcell instability was obtained. It was found that the condition of the Thompson or the Raman regimes of excitation does not depend on…

Accelerator Physics · Physics 2017-02-02 M. A. Kutlan

The energy transition is causing many stability-related challenges for power systems. Transient stability refers to the ability of a power grid's bus angles to retain synchronism after the occurrence of a major fault. In this paper a…

Optimization and Control · Mathematics 2021-01-12 Tim Aschenbruck , Willem Esterhuizen , Stefan Streif

We study numerically the nonlinear dynamics of a shear banding interface in two dimensional planar shear flow, within the non-local Johnson Segalman model. Consistent with a recent linear stability analysis, we find that an initially flat…

Soft Condensed Matter · Physics 2009-11-11 Suzanne M. Fielding , Peter D. Olmsted

The gravito-inertial waves propagating over a shellular baroclinic flow inside a rotating spherical shell are analysed using the Boussinesq approximation. The wave properties are examined by computing paths of characteristics in the…

Solar and Stellar Astrophysics · Physics 2016-08-24 Giovanni M. Mirouh , Clément Baruteau , Michel Rieutord , Jérôme Ballot

Double-resonant extremely asymmetrical scattering (DEAS) is a strongly resonant type of Bragg scattering in two joint or separated uniform gratings with different phases. It is characterised by a very strong increase of the scattered and…

Optics · Physics 2007-05-23 Dmitri K. Gramotnev , Timo A. Nieminen

We analyze the stability of a non-Hermitian coupler with respect to modulational inhomogeneous perturbations in the presence of unbalanced gain and loss. At the parity-time (PT) symmetry point the coupler is unstable. Suitable symmetry…

Pattern Formation and Solitons · Physics 2017-06-28 Yannis Kominis , Tassos Bountis , Sergej Flach

The instabilities of the nontrivial phase elliptic solutions in a repulsive Bose-Einstein condensate (BEC) with a periodic potential are investigated. Based on the defocusing nonlinear Schr\"{o}dinger (NLS) equation with an elliptic…

Pattern Formation and Solitons · Physics 2023-05-02 Wen-Rong Sun , Jin-Hua Li , Lei Liu , P. G. Kevrekidis

Balanced gain and loss leads to stationary dynamics in open systems. This occurs naturally in PT-symmetric systems, where the imaginary part of the potential describing gain and loss is perfectly antisymmetric. While this case seems…

Quantum Physics · Physics 2020-09-22 Daniel Dizdarevic , Holger Cartarius , Jörg Main , Günter Wunner

The self-starting dynamics of a model for passively mode-locked lasers with saturable absorber, in which the optical amplifier has a saturable nonlinearity, is examined. The basic assumption is that the laser will operate in the mode-locked…

Optics · Physics 2020-09-15 Alain M. Dikande , P. Achankeng Leke

In this work, we have studied the traveling wave solution in a nonlinear Bragg grating structure in which the core of the optical fiber is having Parity-time (PT) symmetric refractive index distribution. We have found bright solitary wave…

Optics · Physics 2017-10-25 Samit Kumar Gupta , Amarendra K. Sarma

Extremely asymmetrical scattering (EAS) is a new type of Bragg scattering in thick, slanted, periodic gratings. It is realised when the scattered wave propagates parallel to the front boundary of the grating. Its most important feature is…

Optics · Physics 2007-05-23 T. A. Nieminen , D. K. Gramotnev

We have investigated linear and nonlinear dynamics of ion-temperature-gradient driven drift mode for Maxwellian and non Maxwellian pair-ion plasma embedded in an inhomogeneous magnetic field having gradients in ion's temperature and number…

Plasma Physics · Physics 2022-09-14 Javaria Razzaq , Zahida Ehsan , Arshad M. Mirza
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