Yu Miao, Liu Kun, Li Min, Yan Jiaqing, Cao Chuanpeng, Tan Jia, Liang Jintai, Guo Keyu, Cao Wei, Lan Pengfei, Zhang Qingbin, Zhou Yueming, Lu Peixiang
Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, 430074, Wuhan, China.
Jiangsu Key Laboratory of Micro and Nano Heat Fluid Flow Technology and Energy Application, School of Physical Science and Technology, Suzhou University of Science and Technology, 215009, Suzhou, China.
Light Sci Appl. 2022 Jul 7;11(1):215. doi: 10.1038/s41377-022-00911-8.
Tunneling is one of the most fundamental and ubiquitous processes in the quantum world. The question of how long a particle takes to tunnel through a potential barrier has sparked a long-standing debate since the early days of quantum mechanics. Here, we propose and demonstrate a novel scheme to accurately determine the tunneling time of an electron. In this scheme, a weak laser field is used to streak the tunneling current produced by a strong elliptically polarized laser field in an attoclock configuration, allowing us to retrieve the tunneling ionization time relative to the field maximum with a precision of a few attoseconds. This overcomes the difficulties in previous attoclock measurements wherein the Coulomb effect on the photoelectron momentum distribution has to be removed with theoretical models and it requires accurate information of the driving laser fields. We demonstrate that the tunneling time of an electron from an atom is close to zero within our experimental accuracy. Our study represents a straightforward approach toward attosecond time-resolved imaging of electron motion in atoms and molecules.
隧穿是量子世界中最基本且普遍存在的过程之一。自量子力学早期以来，关于粒子隧穿势垒需要多长时间的问题就引发了长期的争论。在此，我们提出并演示了一种精确确定电子隧穿时间的新方案。在该方案中，一个弱激光场用于对由处于阿秒光钟配置的强椭圆偏振激光场产生的隧穿电流进行条纹化，从而使我们能够以几阿秒的精度获取相对于场最大值的隧穿电离时间。这克服了以往阿秒光钟测量中的困难，在以往测量中，必须用理论模型去除库仑对光电子动量分布的影响，并且需要驱动激光场的准确信息。我们证明，在我们的实验精度范围内，电子从原子隧穿的时间接近零。我们的研究代表了一种对原子和分子中电子运动进行阿秒时间分辨成像的直接方法。
