強場雷射中原子的超閾值電離譜：近核區域波包的第一原理計算

Abstract

本文提出了新的數值方法，用無自我交互作用的時變孔恩-沈方程 式來處理非微擾的多光子游離、超閾值電離。因為在此我們不需要處 理離核很遠處的波函數的時間演化，所以這個方法不但精確也很省 時。這方法是建立在將波函數從實驗室座標轉換到 Kramers-Henneberger 框架上，我們把這方法應用到惰性氣體的超閾值 電離。在此我們計算電子的能譜跟其角度分布，結果顯示了電子頻譜 與雷射強度、頻率、載波包相位的相依性，並跟實驗作比較。

We present a new method for the the numerical solution of the self-interaction-free time-dependent Kohn-Sham equation for the nonperturbative treatment of multiphoton ionization (MPI), above-threshold ionization (ATI), and electron energy and angular distribution after ATI. The method is accurate and efficient because we don’t need to perform the propagation of the time-dependent wave function to the large distance. The procedure is based on the extension of the Kramers-Henneberger picture of the ionization process while the initial expressions involve the wave function in the laboratory frame only. This approach is applied to the accurate study of ATI processes of the rare gas atoms subject to intense laser pulse. We calculate and discuss ejected electron energy and angular distributions. The results reveal the electron spectrum dependence on the duration of the laser pulse and the carrier-envelope phase.