Application of discrete variable representation to planar H2+ in strong xuv laser fields.
Application of discrete variable representation to planar H2+ in strong xuv laser fields.
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DOI：
10.1063/1.4748137
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发表时间：
2012-09
期刊：
影响因子：
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通讯作者：
Q. Ning;Liang-You Peng;X. Hou;Zhen-Hao Xu;Q. Gong
中科院分区：
文献类型：
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作者：
Q. Ning;Liang-You Peng;X. Hou;Zhen-Hao Xu;Q. Gong
本文提出了一种高效率、高精度的网格方法来研究平面H（2）（+）在Born-Oppenheimer近似下的强场动力学。在平面H（2）（+）中引入椭圆坐标后，我们证明了可以成功地克服核上的库仑奇异性，从而可以用分离变量法精确地计算束缚态和连续态。含时薛定谔方程（TDSE）可以通过二维离散变量表示（DVR）方法精确求解，其中径向坐标用有限元离散变量表示离散，便于并行计算，角坐标用三角形DVR离散，可以描述该方向的周期性。用TDSE的虚时间传播法可以精确地计算束缚态能量，其结果与分离变量法的计算结果吻合得很好。利用TDSE研究了平面H（2）（+）在极紫外短脉冲作用下的电离动力学，得到了与最低阶微扰理论计算结果一致的微分动量分布.
We present an efficient and accurate grid method to study the strong field dynamics of planar H(2)(+) under Born-Oppenheimer approximation. After introducing the elliptical coordinates to the planar H(2)(+), we show that the Coulomb singularities at the nuclei can be successfully overcome so that both bound and continuum states can be accurately calculated by the method of separation of variables. The time-dependent Schrödinger equation (TDSE) can be accurately solved by a two-dimensional discrete variable representation (DVR) method, where the radial coordinate is discretized with the finite-element discrete variable representation for easy parallel computation and the angular coordinate with the trigonometric DVR which can describe the periodicity in this direction. The bound states energies can be accurately calculated by the imaginary time propagation of TDSE, which agree very well with those computed by the separation of variables. We apply the TDSE to study the ionization dynamics of the planar H(2)(+) by short extreme ultra-violet (xuv) pulses, in which case the differential momentum distributions from both the length and the velocity gauge agree very well with those calculated by the lowest order perturbation theory.