Strong-field double ionization through sequential release from double excitation with subsequent Coulomb scattering.
We perform a triple coincidence study on differential momentum distributions of strong-field double ionization of Ar atoms in linearly polarized fields (795 nm, 45 fs, 7×10(13)  W/cm2). Using a three-dimensional two-electron atomic-ensemble semiclassical model including the tunneling effect for both electrons, we retrieve differential momentum distributions and achieve a good agreement with the measurement. Ionization dynamics of the correlated electrons for the side-by-side and back-to-back emission is analyzed separately. According to the semiclassical model, we find that the doubly excited states are largely populated after the laser-assisted recollision and large amounts of double ionization dominantly takes place through sequential ionization of doubly excited states at such a low laser intensity. Compared with the Coulomb-free and Coulomb-corrected sequential tunneling models, we verify that electrons can obtain an energy as large as ∼6.5U p through Coulomb scattering in the combined laser and doubly charged ionic fields.
Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, 100871 Beijing, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China and Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany.
Yunquan
Y
Liu
Center for Applied Physics and Technology, Peking University, 100084 Beijing, China and Institute of Applied Physics and Computational Mathematics, 100088 Beijing, China.
Libin
L
Fu
Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany and Institute of Applied Physics and Computational Mathematics, 100088 Beijing, China.
Difa
D
Ye
Center for Applied Physics and Technology, Peking University, 100084 Beijing, China and Institute of Applied Physics and Computational Mathematics, 100088 Beijing, China.
Jie
J
Liu
Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, 100871 Beijing, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Min
M
Li
Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, 100871 Beijing, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Chengyin
C
Wu
Department of Physics and State Key Laboratory for Mesoscopic Physics, Peking University, 100871 Beijing, China and Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
Qihuang
Q
Gong
Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany.
R
R
Moshammer
Max-Planck-Institut für Kernphysik, D-69117 Heidelberg, Germany and Physikalisch-Technische Bundesanstalt, Bundesallee 100, D-38116 Braunschweig, Germany.
J
J
Ullrich