Jiang Wei-Chao, Zhong Ming-Chen, Fang Yong-Kang, Donsa Stefan, Březinová Iva, Peng Liang-You, Burgdörfer Joachim
Shenzhen University, Institute of Quantum Precision Measurement, College of Physics and Optoelectronic Engineering, Shenzhen 518060, China.
Peking University, State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics, School of Physics, Beijing 100871, China.
Phys Rev Lett. 2024 Oct 18;133(16):163201. doi: 10.1103/PhysRevLett.133.163201.
Attosecond chronoscopy enables the exploration of correlated electron dynamics in real time. One key observable of attosecond physics is the determination of "time zero" of photoionization, the time delay with which the wave packet of the ionized electron departs from the ionic core. This observable has become accessible by experimental advances in attosecond streaking and reconstruction of attosecond beating by interference of two-photon transitions (RABBIT) techniques. In this Letter, we explore photoionization time delays by strong extreme ultraviolet fields beyond the linear-response limit. We identify novel signatures in time delays signifying strong coupling between atoms and light fields and the light-field dressing of the ion. As a prototypical case, we study the interelectronic coherence and entanglement in helium driven by a strong extreme ultraviolet field. By the numerical solution of the time-dependent Schrödinger equation in its full dimensionality, we show that the time delay of the photoionized electron allows one to monitor the ultrafast variations of coherence dynamics and entanglement in real time.
阿秒时间分辨技术能够实时探索相关电子动力学。阿秒物理的一个关键可观测现象是光致电离“时间零点”的确定，即电离电子波包从离子核出发的时间延迟。通过阿秒条纹技术以及双光子跃迁干涉重建阿秒拍频（RABBIT）技术的实验进展，这个可观测现象已能实现。在本信函中，我们通过超出线性响应极限的强极紫外场来探索光致电离时间延迟。我们在时间延迟中识别出了新的特征，这些特征表明原子与光场之间存在强耦合以及离子的光场修饰。作为一个典型案例，我们研究了由强极紫外场驱动的氦气中的电子间相干性和纠缠。通过对含时薛定谔方程进行全维度数值求解，我们表明光致电离电子的时间延迟能够让人实时监测相干动力学和纠缠的超快变化。
