State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China.
Beijing Academy of Quantum Information Sciences, Beijing 100193, China.
Phys Rev Lett. 2019 Feb 8;122(5):053201. doi: 10.1103/PhysRevLett.122.053201.
In laser-matter interaction, most previous studies have focused on the change of the electron momentum induced by the external fields. Here, we theoretically investigate the electron displacement induced by an ultrashort pulse, whose precise waveform is hard to determine experimentally. We propose and numerically demonstrate a scheme to accurately measure the electron displacement using a ruler formed by the interfering spirals in the photoelectron momentum distribution generated by two oppositely circularly polarized pulses. The scheme is robust against the focusing volume effects and the jitter of the carrier envelope phase of the two circular pulses. The ability to measure the electron displacement by an arbitrary pulse may pave the way to quantitative control of the charge migration in matter on the scale of Ångström.
在激光与物质相互作用中，大多数先前的研究都集中在外场引起的电子动量变化上。在这里，我们从理论上研究了由超短脉冲引起的电子位移，而该脉冲的精确波形很难在实验中确定。我们提出并数值证明了一种方案，通过使用由两个相反圆偏振脉冲产生的光电子动量分布中的干涉螺旋形成的“标尺”，可以精确地测量电子位移。该方案对聚焦体积效应和两个圆脉冲载波包络相位的抖动具有鲁棒性。通过任意脉冲测量电子位移的能力可能为在埃尺度上定量控制物质中的电荷迁移铺平道路。
