Time-resolved X-ray photoelectron spectroscopy (TXPS) is a powerful technique for probing coherent nuclear wavepacket dynamics. However, energy resolution is compromised for very short pulse durations. This study theoretically demonstrates how the complete information of a nuclear wavepacket (populations and relative phases of vibrational states) can be retrieved from time-resolved resonant Auger-electron spectroscopy (TRAS) measurements using resonantly tuned attosecond X-ray pulses. TRAS offers key insights into coupled nuclear and electronic dynamics on ultrashort timescales, providing an alternative to leverage femtosecond and attosecond X-ray probe pulses.

Chao Wang, Maomao Gong, Xi Zhao, Quan Wei Nan, Xin Yue Yu, Yongjun Cheng, Victor Kimberg, Xiao-Jing Liu, Oriol Vendrell, Kiyoshi Ueda, Song Bin Zhang