Carl von Ossietzky Universität Oldenburg, Institut für Physik, Carl-von-Ossietzky-Straße 9-11, D-26129, Oldenburg, Germany.
Nat Commun. 2019 Feb 8;10(1):658. doi: 10.1038/s41467-019-08601-7.
Polarization-tailored bichromatic femtosecond laser fields with cycloidal polarization profiles have emerged as a powerful tool for coherent control of quantum processes. We present an optical scheme to create and manipulate three-dimensional free electron wave packets with arbitrary rotational symmetry by combining advanced supercontinuum pulse shaping with high resolution photoelectron tomography. Here we use carrier-envelope phase-stable polarization-tailored bichromatic (3ω:4ω) counter- and corotating femtosecond laser pulses to generate 7-fold rotational symmetric and asymmetric photoelectron momentum distributions by multiphoton ionization of sodium atoms. To elucidate the physical mechanisms, we investigate the interplay between the symmetry properties of the driving field and the resulting electron wave packets by varying the optical field parameters. Our results show that the symmetry properties of electron wave packets are not fully determined by the field symmetry, but completely described by multipath quantum interference of states with different angular momenta.
具有回旋偏振分布的偏振调谐双色飞秒激光场已成为相干控制量子过程的有力工具。我们提出了一种光学方案，通过结合先进的超连续脉冲整形和高分辨率光电子断层扫描，利用任意旋转对称性的三维自由电子波包。在这里，我们使用载波包络相位稳定的偏振调谐双色（3ω：4ω）对转和共转飞秒激光脉冲，通过多光子电离钠原子产生 7 倍旋转对称和非对称光电子动量分布。为了阐明物理机制，我们通过改变光场参数研究了驱动场的对称性质与所得电子波包之间的相互作用。我们的结果表明，电子波包的对称性质不是完全由场对称决定的，而是由不同角动量状态的多路径量子干涉完全描述的。
