title: Characteristic spectrum of very low-energy photoelectron from above-threshold ionization in the tunneling regime.
abstract: We report an experimental and theoretical study of very low-energy photoelectrons in tunneling ionization process from noble gas atoms interacting with ultrashort intense infrared laser pulses. A universal peak structure with electron energy well below 1 eV in the photoelectron spectrum, corresponding to the double-hump structure in the longitudinal momentum distribution, is identified experimentally for all atomic species. Our quantum and semiclassical analysis reveal the role of long-range Coulomb potential in the production of this very low-energy peak structure.
authors.affiliation: State Key Laboratory for Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871, China. cywu@pku.edu.cn
authors.forename: C Y
authors.initials: CY
authors.lastname: Wu
authors.forename: Y D
authors.initials: YD
authors.lastname: Yang
authors.forename: Y Q
authors.initials: YQ
authors.lastname: Liu
authors.forename: Q H
authors.initials: QH
authors.lastname: Gong
authors.forename: M
authors.initials: M
authors.lastname: Wu
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: X L
authors.initials: XL
authors.lastname: Hao
authors.forename: W D
authors.initials: WD
authors.lastname: Li
authors.forename: X T
authors.initials: XT
authors.lastname: He
authors.forename: J
authors.initials: J
authors.lastname: Chen