Chen Xiang, Ruiz Camilo, He Feng, Zhang Jie
Opt Express. 2020 May 11;28(10):14884-14896. doi: 10.1364/OE.391138.
We investigate the double ionization of a model Neon atom in strong middle infrared laser pulses by simulating the classical trajectories of the electron ensemble. After one electron tunnels out from the laser-dressed Coulomb barrier, it might undergo different returning trajectories depending on its initial transverse momentum, which in this wavelength may propagate along or deviate from the polarization direction. This initial transverse momentum determines the rescattering time, and thus some trajectories can have returning time longer than one optical cycle. These late-returning trajectories determine the correlated electron-electron momentum distribution for double ionization and allow us to disentangle each double ionization event from the final momentum distribution. The description of these trajectories allow us also to understand how the nondipole effects modify the correlated electron-electron momentum distribution in double ionization.
我们通过模拟电子系综的经典轨迹，研究了强中红外激光脉冲作用下模型氖原子的双电离过程。一个电子从激光修饰的库仑势垒隧穿出去后，根据其初始横向动量，可能会经历不同的返回轨迹，在这个波长下，它可能沿偏振方向传播或偏离偏振方向。这个初始横向动量决定了再散射时间，因此一些轨迹的返回时间可能会超过一个光学周期。这些延迟返回的轨迹决定了双电离中电子 - 电子关联动量分布，并使我们能够从最终动量分布中区分出每个双电离事件。对这些轨迹的描述还使我们能够理解非偶极效应如何改变双电离中电子 - 电子关联动量分布。
