Buildup time of Autler-Townes splitting in attosecond transient absorption spectroscopy

作     者：Xiaoxia Wu Zengqiang Yang Shaofeng Zhang Xinwen Ma Jie Liu Difa Ye 

作者机构：Institute of Modern Physics Chinese Academy of Sciences Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China Laboratory of Computational Physics Institute of Applied Physics and Computational Mathematics Beijing 100088 China Department of Physics School of Arts and Sciences Shaanxi University of Science and Technology Xi'an 710021 China Graduate School China Academy of Engineering Physics Beijing 100193 China 

出 版 物：《Physical Review A》 (Phys. Rev. A)

年 卷 期：2021年第103卷第6期

页      面：L061102-L061102页

核心收录：

基　　金：Scientific Research Foundation of SUST, (2017BJ-30) National Natural Science Foundation of China, NSFC, (11674034, 11775030, 11822401) Education Department of Shaanxi Province, (18JK0098) National Key Research and Development Program of China, NKRDPC, (2017YFA0402300) National Safety Academic Fund, NSAF, (U1930403) 

主　　题：Nonlinear optics Optical transient phenomena Stark effect Ultrafast optics Ultrafast phenomena Adiabatic approximation Rotating wave approximation Schroedinger equation Two-level models 

摘      要：Although the time-dependent buildup processes of Autler-Townes splitting in attosecond transient absorption spectra have been observed in plenty of experiments, there still exists an open question of when the splitting is maximized, which tells us how fast the system responds to the pump field and how well the adiabatic following is in a slowly varying few-cycle laser pulse. In this Letter we work out a compact formula to quantify the buildup time of the Autler-Townes splitting, which is related to multiple timescales of the laser-atom system, e.g., the Rabi period, the laser cycle, and the pulse duration, according to a universal power law. This scaling law applies not only to singly excited states, but also to doubly excited states in which complex electron-electron interaction gets involved. Our findings have potential applications in calibrating the zero delay in a transient absorption spectroscopy.