Department of Physics, Lund University, P.O. Box 118, SE-22 100 Lund, Sweden.
Department of Physics, University of Gothenburg, Origovägen 6B, SE-41 296 Göteborg, Sweden.
Science. 2017 Nov 17;358(6365):893-896. doi: 10.1126/science.aao7043. Epub 2017 Nov 2.
Ultrafast processes in matter, such as the electron emission after light absorption, can now be studied using ultrashort light pulses of attosecond duration (10 seconds) in the extreme ultraviolet spectral range. The lack of spectral resolution due to the use of short light pulses has raised issues in the interpretation of the experimental results and the comparison with theoretical calculations. We determine photoionization time delays in neon atoms over a 40-electron volt energy range with an interferometric technique combining high temporal and spectral resolution. We spectrally disentangle direct ionization from ionization with shake-up, in which a second electron is left in an excited state, and obtain excellent agreement with theoretical calculations, thereby solving a puzzle raised by 7-year-old measurements.
超快过程在物质中，例如电子发射后的光吸收，可以现在用飞秒光脉冲（10 秒）在极端紫外光谱范围内进行研究。由于使用短光脉冲缺乏光谱分辨率，这在实验结果的解释和与理论计算的比较中引发了问题。我们使用一种结合了高时间和光谱分辨率的干涉技术，在 40 电子伏特的能量范围内确定氖原子的光离化时间延迟。我们从具有摇晃的光离化中（其中第二个电子留在激发态）中分光解析直接光离化，并且与理论计算非常吻合，从而解决了 7 年前测量提出的一个难题。
