Ultrafast Dynamics And Coherent Manipulation Of Atomic Inner-shell Transitions Induced By X-ray Lasers

The booming development of X-ray free electron laser(XFEL)provides the golden opportunity to study of atom and molecule dynamics at extreme conditions in recent ten years.X-ray pulse with ultra-short duration and ultra-high intensity triggers the atomic inner-shell transition,which extends the non-linear and non-perturbation dynamics of laser-matter interactions to X-ray regime.Under this circumstance,the time-dependent theory with single-electron approximation or mean-field approximation would not be suit-able.The urgency has been put forward to develop the appropriate theory and method to present detailed study on the interactions between X-ray laser and atomic inner-shell elec-trons.In this Ph D thesis,we present the in-depth investigation on the ultrafast dynamics and coherent manipulation of atomic inner-shell transitions induced by X-ray lasers,based on the framework of open quantum system and quantum master equation.The main con-tent consist of three parts as follows:First,we studied the two-photon double ionization processes of 2s electrons of neon under the attosecond extreme ultra-violent laser.According to the quantum master equa-tion with the formation of anti-symmetry coupled two-electron wavefunction,we found the remarkable kinetics energy sharing in two-electron spectrum under short pulse dura-tion,which derives from the undistinguished ionization channels.And the role of dephas-ing,including the hotoionzation of 2p electron and spontaneous decay,would hinder the correlation effcts as well as the destruction of scaling law.It shows the importance of dephasing factors in the inner-shell dynamics even within attosecond timescale.Second,we studied the dynamical effects in the product of double-core-hole states of neon 1s-shell in X-ray attosecond pump-attosecond probe proposal.Based on the large-scale simulations of Monte-Carlo wavefunction method,we found the distinct ab-sorption lines of different Rydberg double-core-hole states and the Stark shift as well as the quantum interference effects under the dephasing effects with strong Auger decay and photoionization processes.It indicates the transient modulations derive from the Raman channel.We also found the non-perturbation under high intensity.Considering the par-tially coherent X-ray pulses,there is still the distinct dynamical effects in the transient absorption spectrum.Third,we studied coherence modulations of Mg~+atomic inner-shell Kαtransitions pumped by XFEL.Based on the simultaneous formations of Maxwell equations and quan-tum master equations,we found the X-ray lasers with high-order sidebands and attosecond duration are amplified during the propagation with the modulation of quasi-continuous wave and few-cycle infrared lasers,respectively.The frequency of modulated X-ray pulses can extend to higher energy level by selecting the appropriate inner-shell tran-sition of atoms.In the complex plasma surroundings with low-density condition,even though Auger decay,coherence-limited XFEL,multichannel coupling,collisional transi-tions,etc would hinder the effect of coherent modulations,the two schemes as mentioned above still present the modulated X-ray pulses with high flux,high conversion efficiency and coherence feature.