Electron Vortices in Femtosecond Multiphoton Ionization
Electron Vortices in Femtosecond Multiphoton Ionization
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DOI：
10.1103/physrevlett.118.053003
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发表时间：
2017-02-02
影响因子：
8.6
通讯作者：
Wollenhaupt, M.
中科院分区：
文献类型：
--
作者：
Pengel, D.;Kerbstadt, S.;Wollenhaupt, M.
在两个反向旋转的圆偏振飞秒激光脉冲作用下，钾原子的多光子电离在描述阿基米德螺线的极化平面上产生旋涡状的光电子动量分布。通过极化整形产生脉冲序列，并根据速度图成像测量结果层析重建三维光电子分布。我们发现微扰电离导致了具有c(6)旋转对称性的电子涡旋。对于非微扰相互作用，证明了涡旋的旋转对称性从c(6)变为c(4)。
Multiphoton ionization of potassium atoms with a sequence of two counter-rotating circularly polarized femtosecond laser pulses produces vortex-shaped photoelectron momentum distributions in the polarization plane describing Archimedean spirals. The pulse sequences are produced by polarization shaping and the three-dimensional photoelectron distributions are tomographically reconstructed from velocity map imaging measurements. We show that perturbative ionization leads to electron vortices with c(6) rotational symmetry. A change from c(6) to c(4) rotational symmetry of the vortices is demonstrated for nonperturbative interaction.