Diffraction Managed Solitons with Zero Mean Diffraction

The problem of existence of soliton solutions in a diffraction managed NLS is considered in the case of zero mean diffraction. Existence of localized breather solutions for the averaged equation is shown using Ekeland’s variational principle in the corresponding minimization of the Hamiltonian procedure. The corresponding minimizer is shown to be spatially well-localized and orbitally stable.      

SPACE-TIME FINITE ELEMENT METHOD FOR SCHRODINGER EQUATION AND ITS CONSERVATION

Energy conservation of nonlinear Schrodinger ordinary differential equation was proved through using continuous finite element methods of ordinary differential equation; Energy integration conservation was proved through using space-time continuous fully discrete finite element methods and the electron nearly conservation with higher order error was obtained through using time discontinuous only space continuous finite element methods of nonlinear Schrodinger partial equation. The numerical results are in accordance with the theory.     

非自治耗散Schr\"odinger-Boussinesq 方程组紧致核截面的存在性$^$

讨论满足齐次Dirichlet边界条件的非自治耗散Schr\"odinger-Boussinesq 方程组解的长时间行为. 通过 对方程作适当的分解, 证明了方程组所生成的过程存在紧致核截面.     

Chaos control in the nonlinear Schrodinger equation with Kerr law nonlinearity

The nonlinear Schr6dinger equation with Kerr law nonlinearity in the two-frequency interference is studied by the numerical method. Chaos occurs easily due to the absence of damping. This phenomenon will cause the distortion in the process of information transmission. We find that fiber-optic transmit signals still present chaotic phenomena if the control intensity is smaller. With the increase of intensity, the fiber-optic signal can stay in a stable state in some regions. When the strength is suppressed to a certain value, an unstable phenomenon of the fiber-optic signal occurs. Moreover we discuss the sensitivities of the parameters to be controlled. The results show that the linear term coefficient and the environment of two quite different frequences have less effects on the fiber-optic transmission. Meanwhile the phenomena of vibration, attenuation and escape occur in some regions.     

A new finite difference scheme for a dissipative cubic nonlinear Schr6dinger equation

This paper considers the one-dimensional dissipative cubic nonlinear SchrSdinger equation with zero Dirichlet boundary conditions on a bounded domain. The equation is discretized in time by a linear implicit three-level central difference scheme, which has analogous discrete conservation laws of charge and energy. The convergence with two orders and the stability of the scheme are analysed using a priori estimates. Numerical tests show that the three-level scheme is more efficient.     

Schrödinger soliton from Lorentzian manifolds

In this paper, we introduce a new notion named as Schrödinger soliton. The so-called Schrödinger solitons are a class of solitary wave solutions to the Schrödinger flow equation from a Riemannian manifold or a Lorentzian manifold M into a Kähler manifold N. If the target manifold N admits a Killing potential, then the Schrödinger soliton reduces to a harmonic map with potential from M into N. Especially, when the domain manifold M is a Lorentzian manifold, the Schrödinger soliton is a wave map with potential into N. Then we apply the geometric energy method to this wave map system, and obtain the local well-posedness of the corresponding Cauchy problem as well as global existence in 1+1 dimension. As an application, we obtain the existence of Schrödinger soliton solution to the hyperbolic Ishimori system.     

New Ans(a)tze for Obtaining Exact Solutions of Nonlinear Schr(o)dinger-Type Equation

We propose two simple ans(a)tze that allow us to obtain different analytical solutions for two generalized versions of the nonlinear Schr(o)dinger equation, such as the averaged dispersive-managed fiber system equation and the extended nonlinear Schr(o)dinger equation which describe the femtosecond pulse propagation in monomode optical fiber.Among these solutions we can find solitary wave and periodic wave solutions representing the propagation of different waveforms in nonlinear media.     

非等谱广义耦合非线性Schrdinger方程的局部化孤立波(英文)

利用Hirota双线性方法求解了一个非等谱广义耦合非线性Schr(o|¨)dinger方程,得到它的N-孤子解.其中单孤子可以描述一个任意大振幅且具有时间和空间双重局部性的孤立波,这种特征与所谓的"怪波"相一致.此外,借助于图像描述了二孤子的相互作用.     

布洛赫电子的拓扑与几何

文章回顾了电子的拓扑几何理论发展的初期,大约二十多年的历史。首先介绍拓扑陈数在凝聚态物理中的两个重要应用。其一关于量子霍尔效应,绝缘条件下霍尔电导可以写成一个陈数拓扑不变量,从而解释实验结果的精确量子化。其二关于绝热泵浦,它描述布洛赫能带的绝热电流响应,与电子极化有密切联系。拓扑陈数是布里渊区上贝里曲率的积分,后者本身也有独立的物理意义。接着介绍贝里曲率对电子动力学的影响,包括反常速度和轨道磁化等概念。作者还将这个理论推广到多带情况,使其可以应用到自旋输运等现象。最后,文中展示了再量子化方法,从半经典模型来获得布洛赫电子的有效量子理论。在非相对论极限下,泡利—薛定谔方程可以看作是狄拉克电子在正能谱上的等效量子理论,其中的自旋轨道耦合即是一种几何物理效应。     

Approximate analytical solutions and mean energies of stationary Schrödinger equation for general molecular potential

The Schrödinger equation is solved with general molecular potential via the improved quantization rule. Expression for bound state energy eigenvalues, radial eigenfunctions, mean kinetic energy, and potential energy are obtained in compact form. In modeling the centrifugal term of the effective potential, a Pekeris-like approximation scheme is applied. Also, we use the Hellmann-Feynman theorem to derive the relation for expectation values. Bound state energy eigenvalues, wave functions and meanenergies of Woods-Saxon potential, Morse potential, Möbius squared and Tietz-Hua oscillators are deduced from the general molecular potential. In addition, we use our equations to compute the bound state energy eigenvalues and expectation values for four diatomic molecules viz. H₂, CO, HF, and O₂. Results obtained are in perfect agreement with the data available from the literature for the potentials and molecules. Studies also show that as the vibrational quantum number increases, the mean kinetic energy for the system in a Tietz-Hua potential increases slowly to a threshold value and then decreases. But in a Morse potential, the mean kinetic energy increases linearly with vibrational quantum number increasing.