Stable Magnetostatic Solitons in Yttrium Iron Garnet Film Waveguides for Tilted in-Plane Magnetic Fields

The possibility of nonlinear pulses generation in Yttrium Iron Garnet thin films for arbitrary direction between waveguide and applied static in-plane magnetic field is considered. Up to now only the cases of in-plane magnetic fields either perpendicular or parallel to waveguide direction have been studied both experimentally and theoretically. In the present paper it is shown that also for other angles (besides 0 or 90 degrees) between a waveguide and static in-plane magnetic field the stable bright or dark (depending on magnitude of magnetic field) solitons could be created.Comment: Phys. Rev. B (accepted, April 1, 2002

Interaction Properties of the Periodic and Step-like Solutions of the Double-Sine-Gordon Equation

The periodic and step-like solutions of the double-Sine-Gordon equation are investigated, with different initial conditions and for various values of the potential parameter $\epsilon$. We plot energy and force diagrams, as functions of the inter-soliton distance for such solutions. This allows us to consider our system as an interacting many-body system in 1+1 dimension. We therefore plot state diagrams (pressure vs. average density) for step-like as well as periodic solutions. Step-like solutions are shown to behave similarly to their counterparts in the Sine-Gordon system. However, periodic solutions show a fundamentally different behavior as the parameter $\epsilon$ is increased. We show that two distinct phases of periodic solutions exist which exhibit manifestly different behavior. Response functions for these phases are shown to behave differently, joining at an apparent phase transition point.Comment: 17pages, 15 figure

Solitons in polarized double layer quantum Hall systems

A new manifestation of interlayer coherence in strongly polarized double layer quantum Hall systems with total filling factor $\nu=1$ in the presence of a small or zero tunneling is theoretically predicted. It is shown that moving (for small tunneling) and spatially localized (for zero tunneling) stable pseudospin solitons develop which could be interpreted as mobile or static charge-density excitations. The possibility of their experimental observation is also discussed.Comment: Phys. Rev. B (accepted

Two interacting particles in a random potential

We study the scaling of the localization length of two interacting particles in a one-dimensional random lattice with the single particle localization length. We obtain several regimes, among them one interesting weak Fock space disorder regime. In this regime we derive a weak logarithmic scaling law. Numerical data support the absence of any strong enhancement of the two particle localization length

Nonlinear Dynamics in Double Square Well Potential

Considering the coherent nonlinear dynamics in double square well potential we find the example of coexistence of Josephson oscillations with a self-trapping regime. This macroscopic bistability is explained by proving analytically the simultaneous existence of symmetric, antisymmetric and asymmetric stationary solutions of the associated Gross-Pitaevskii equation. The effect is illustrated and confirmed by numerical simulations. This property allows to make suggestions on possible experiments using Bose-Einstein condensates in engineered optical lattices or weakly coupled optical waveguide arrays

Pattern formation and localization in the forced-damped FPU lattice

We study spatial pattern formation and energy localization in the dynamics of an anharmonic chain with quadratic and quartic intersite potential subject to an optical, sinusoidally oscillating field and a weak damping. The zone-boundary mode is stable and locked to the driving field below a critical forcing that we determine analytically using an approximate model which describes mode interactions. Above such a forcing, a standing modulated wave forms for driving frequencies below the band-edge, while a ``multibreather'' state develops at higher frequencies. Of the former, we give an explicit approximate analytical expression which compares well with numerical data. At higher forcing space-time chaotic patterns are observed.Comment: submitted to Phys.Rev.

Fano Resonances in Flat Band Networks

Linear wave equations on Hamiltonian lattices with translational invariance are characterized by an eigenvalue band structure in reciprocal space. Flat band lattices have at least one of the bands completely dispersionless. Such bands are coined flat bands. Flat bands occur in fine-tuned networks, and can be protected by (e.g. chiral) symmetries. Recently a number of such systems were realized in structured optical systems, exciton-polariton condensates, and ultracold atomic gases. Flat band networks support compact localized modes. Local defects couple these compact modes to dispersive states and generate Fano resonances in the wave propagation. Disorder (i.e. a finite density of defects) leads to a dense set of Fano defects, and to novel scaling laws in the localization length of disordered dispersive states. Nonlinearities can preserve the compactness of flat band modes, along with renormalizing (tuning) their frequencies. These strictly compact nonlinear excitations induce tunable Fano resonances in the wave propagation of a nonlinear flat band lattice

Important problems in the diagnosis and treatment of autoimmune hepatitis (based on the Russian consensus 2017)

The analysis of publications devoted to the Russian Consensus on the Diagnostic and Treatment of Autoimmune Hepatitis (AIH), which was considered at the 43rd annual Scientific Session of the CNIIG From Traditions to Innovation (March 4, 2017) is carried out. The presence of clear algorithms and recommendations for the diagnosis and treatment of AIH significantly help the doctor in real clinical practice, but do not exclude a personified approach to the patient

Effectiveness of mebeverine in patients with post-cholecystectomy gastrointestinal spasm: results of prospective observational program “odyssey”

Aim: to assess the effectiveness of mebeverine 200 mg BID in patients with post-cholecystectomy gastrointestinal spasm not requiring surgical treatment. Materials and methods. 218 patients were included in 16 clinical centers in 14 cities in Russia. All patients had post-cholecystectomy gastrointestinal spasms, not requiring surgical treatment and received mebeverine (Duspatalin®) 200 mg BID. The observational assessment period lasted from the moment of their inclusion into the study up to 6 weeks post inlusion. The therapy results were evaluated using visual analog scales (GPA and 11-point numeric rating scale) by patient self-assessment of the dynamics of spasm/discomfort and other post-cholecystectomic gastrointestinal symptoms after 2 and 6 weeks of treatment. Gastrointestinal Quality of Life Index (GIQLI) was used to assess patient quality of life. Results and discussion. All 218 patients completed the 2-week mebeverine treatment course, 101 of them finished the 6-week course (“prolonged population”). Significant positive changes in the relief of abdominal pain and dyspepsia were noted as well as normalization of stool frequency and consistency. A more marked change in values was observed during prolonged (up to 6 weeks) therapy. Both 2-week and 6-week mebeverine courses led to a normalization of patient quality of life. After 6 week therapy, an effect of mebeverine on the quality of life 91% of patients was observed comparable to cholecystectomy itself, speficially related to the quality of life subscore ‘symptoms’. Conclusion. The results of our study demonstrate that mebeverine (Duspatalin®) therapy leads to an effective elimination of clinical symptoms associated with post-cholecystectomy GI-spasm disorders, like abdominal pain, symptoms of dyspepsia and stooldisorders. A more marked change in values was observed during prolonged (up to 6 weeks) therapy

Classical Simulation of Relativistic Quantum Mechanics in Periodic Optical Structures

Spatial and/or temporal propagation of light waves in periodic optical structures offers a rather unique possibility to realize in a purely classical setting the optical analogues of a wide variety of quantum phenomena rooted in relativistic wave equations. In this work a brief overview of a few optical analogues of relativistic quantum phenomena, based on either spatial light transport in engineered photonic lattices or on temporal pulse propagation in Bragg grating structures, is presented. Examples include spatial and temporal photonic analogues of the Zitterbewegung of a relativistic electron, Klein tunneling, vacuum decay and pair-production, the Dirac oscillator, the relativistic Kronig-Penney model, and optical realizations of non-Hermitian extensions of relativistic wave equations.Comment: review article (invited), 14 pages, 7 figures, 105 reference