TDSE方法用于多导体传输线端接动态元件的分析

利用时域空间扩展方法 (TDSE)对多导体传输线端接动态元件的情况进行了分析 ,为电磁兼容分析提供了一种新的途径。利用该方法分别对由独立激励源和入射电磁波激励的传输线的终端感应电压和电流进行了分析。仿真结果表明 :当传输线端接动态元件的时候 ,终端感应电压和电流的过渡过程时间将会变长。

HeTDSE:A GPU based program to solve the full-dimensional time-dependent Schr?dinger equation for two-electron helium subjected to strong laser fields

Electron–electron correlation plays an important role in the underlying dynamics in physics and chemistry.Helium is the simplest and most fundamental two-electron system.The dynamic process of helium in a strong laser field is still a challenging issue because of the large calculation cost.In this study,a graphic processing unit(GPU)open ACC based ab initio numerical simulations package He TDSE is developed to solve the full-dimensional time-dependent Schrodinger equation of helium subjected to a strong laser pulse.He TDSE uses B-spline basis sets expansion method to construct the radial part of the wavefunction,and the spherical harmonic functions is used to express for the angular part.Adams algorithm is employed for the time propagation.Our example shows that He TDSE running on an NVIDIA Kepler K20 GPU can outperform the one on an Intel E5-2640 single CPU core by a factor of 147.He TDSE code package can be obtained from the author or from the author's personal website(doi:10.13140/RG.2.2.15334.45128)directly under the GPL license,so He TDSE can be downloaded,used and modified freely.

基于时域不连续伽辽金算法的时域屏蔽效能分析

[目的]为精确分析金属屏蔽腔的时域屏蔽效能,提出一种基于局部时间步进技术和并行技术的时域不连续伽辽金(DGTD)算法。[方法]利用DGTD算法,对金属屏蔽腔进行全波电磁仿真,进而计算时域屏蔽效能(TDSE);利用局部时间步进(LTS)技术增大时间步长,然后结合并行技术显著缩短计算时间;分析金属屏蔽腔的孔径尺寸、腔体厚度、阵列孔间距等设计参数对时域屏蔽效能的影响。[结果]数值算例结果显示,所提方法正确、有效。[结论]所提方法为电磁屏蔽问题的仿真提供了一种有效的工具,对金属屏蔽腔的设计具有一定的指导意义。

Two-photon double ionization of helium by chirped few-cycle attosecond pulses:From nonsequential to sequential regime

The two-photon double ionization（TPDI） dynamics of helium by chirped attosecond pulses are theoretically studied by solving the two-electron time-dependent Schr o¨dinger equation in its full dimensions. We show that both the differential and the total double ionization probability can be significantly controlled by adjusting the chirp. The dependence of the TPDI on the chirp can be quite different for different photon energies, relying on the central photon energy being in the sequential region, nonsequential region, or translation region. The physics which lead to the chirp dependence for different photon energies are addressed. Present findings are well reproduced by a model based on the second-order time-dependent perturbation theory.

Comparative study of photoionization of atomic hydrogen by solving the one-and three-dimensional time-dependent Schrödinger equations

We develop a numerical scheme for solving the one-dimensional(1D)time-dependent Schrödinger equation(TDSE),and use it to study the strong-field photoionization of the atomic hydrogen.The photoelectron energy spectra obtained for pulses ranging from XUV to near infrared are compared in detail to the spectra calculated with our well-developed code for accurately solving the three-dimensional(3D)TDSE.For XUV pulses,our discussions cover intensities at which the ionization is in the perturbative and nonperturbative regimes.For pulses of 400 nm or longer wavelengths,we distinguish the multiphoton and tunneling regimes.Similarities and discrepancies between the 1D and 3D calculations in each regime are discussed.The observed discrepancies mainly originate from the differences in the transition matrix elements and the energy level structures created in the 1D and 3D calculations.

Solving the time-dependent Schrödinger equation by combining smooth exterior complex scaling and Arnoldi propagator

Abstract We develop a highly efficient scheme for numerically solving the three-dimensional time-dependent Schrödinger equation of the single-active-electron atom in the field of laser pulses by combining smooth exterior complex scaling(SECS)absorbing method and Arnoldi propagation method.Such combination has not been reported in the literature.The proposed scheme is particularly useful in the applications involving long-time wave propagation.The SECS is a wonderful absorber,but its application results in a non-Hermitian Hamiltonian,invalidating propagators utilizing the Hermitian symmetry of the Hamiltonian.We demonstrate that the routine Arnoldi propagator can be modified to treat the non-Hermitian Hamiltonian.The efficiency of the proposed scheme is checked by tracking the time-dependent electron wave packet in the case of both weak extreme ultraviolet(XUV)and strong infrared(IR)laser pulses.Both perfect absorption and stable propagation are observed.

The modeling non-sequential double ionization of helium atom under highintensity femtosecond laser pulses with shielding charge approximation

In this study,we successfully extracted the‘knee structure’for non-sequential double ionization(NSDI)in the helium atom.To achieve this,for the first time,we solved the time-dependent Schrödinger equation in three dimensions for the helium atom,utilizing the shielding charge approximation.Our findings corroborate prior observations by Wang et al[Wang and Eberly,Phys.Rev.Lett.105,083001(2010)],demonstrating that NSDI occurs within a narrower time window in circular polarization compared to linear polarization.As a result,the yield of linear polarization was higher than that of circular polarization,aligning with the previously reported results.Notably,in the case of circular polarization,the time window further narrows with increasing intensity,attributed to a decrease in the time-of-flight.

Efficient Grid Treatment of the Time Dependent Schrodinger Equation for Laser-Driven Molecular Dynamics

We present an efficient method to solve the time dependent Schrodinger equation for modeling the dynamics of diatomic molecules irradiated by intense ultrashort laser pulse without Born-Oppenheimer approximation.By introducing a variable prolate spheroidal coordinates and discrete variable representations of the Hamiltonian,we can accurately and efficiently simulate the motion of both electronic and molecular dynamics.The accuracy and convergence of this method are tested by simulating the molecular structure,photon ionization and high harmonic generation of H_(2)^(+).