Dynamic Interference Photoelectron Spectra in Double Ionization:Numerical Simulation of 1D Helium

We report our numerical simulation on the dynamic interference photoelectron spectra for a one-dimensional （1D） He model exposed to intense ultrashort extreme ultraviolet （XUV） laser pulses. The results demonstrate an unambiguous interference feature in the photoelectron spectra, and the interference is unveiled to originate from the dynamic Stark effect. The interference photoelectron spectra are prompted for intense sub-femtosecond XUV laser pulses in double ionization. The stationary phase picture is corroborated qualitatively in the two-electron system. The ability of probing the dynamic Stark effect by the photoelectron spectra in a pragmatic experiment of single-photon double ionization of He may shed light on further investigation on multi-electron atoms and molecules.

Spider Structure of Photoelectron Momentum Distributions of Ionized Electrons from Hydrogen Atoms for Extraction of Carrier Envelope Phase of Few-Cycle Pulses

The spider structure in the photoelectron momentum distributions(PMDs)of ionized electrons from the hydrogen atom is simulated by solving the time-dependent Schrodinger equation(TDSE).We find that the spider structure exhibits sensitive dependence on carrier envelope phase(CEP)of the few-cycle pulses.To elucidate the striking CEP dependence of the spider structure,we select three physical parameters IL,IR,and IR/IL to quantitatively characterize the variations of the spider structure induced by altering the CEPs.IL is the sum of the left half panel of the transverse cut curves(i.e.,the sum of all the negative momenta along the laser polarization direction),IR is the sum of the right half panel of the transverse cut curves(i.e.,the sum of all the positive momenta along the laser polarization direction),and IR/IL is the ratio between the two sums.These parameters are shown to have monotonic relation with the CEP value,which is exploited to extract the CEPs.We anticipate that our method will be useful for obtaining CEPs encoded in the spider structure of PMDs.