Using sequential strong-field double ionization in a pump–probe scheme we show through calculations how electronic dynamics can be prepared and imaged. Electronic dynamics may arise whenever multiple states of the ion are accessed in the ionization step. The dynamics in the cation influence the rate of the second ionization step and the momentum distribution of the ejected electron, allowing their detailed characterization. We show how the probe step is controlled through spatial propensities of the ionizing orbitals and the energy level structure of the dication. Both the final electronic state of the dication and the spin state of the ejected electron pair can be controlled through the time delay between the two ionizing pulses. We discuss how our results will extend to the preparation and measurement of attosecond electron dynamics.Using sequential strong-field double ionization in a pump–probe scheme we show through calculations how electronic dynamics can be prepared and imaged. Electronic dynamics may arise whenever multiple states of the ion are accessed in the ionization step. The dynamics in the cation influence the rate of the second ionization step and the momentum distribution of the ejected electron, allowing their detailed characterization. We show how the probe step is controlled through spatial propensities of the ionizing orbitals and the energy level structure of the dication. Both the final electronic state of the dication and the spin state of the ejected electron pair can be controlled through the time delay between the two ionizing pulses. We discuss how our results will extend to the preparation and measurement of attosecond electron dynamics.

Journal of Physics B Atomic Molecular and Optical PhysicsJan 28, 201139 citations

Atomic tunneling ionization in a photon picture

Yujun Wang, Brett D. Esry

Bulletin of the American Physical SocietyJun 10, 20150 citations

Two-photon double ionization of atomic beryllium with ultrashort laser pulses

Frank L. Yip, Alicia Palacios, Fernando Martı́n +2 more

We investigate the two-photon double ionization of beryllium atom induced by ultrashort pulses. We use a time-dependent formalism to evaluate the ionization amplitudes and generalized cross sections for the ejection of the $2{s}^{2}$ valence shell electrons in the presence of a fully occupied $1{s}^{2}$ frozen core shell. The relative contributions of the two-photon direct and sequential process are systematically explored by varying both pulse duration and central frequency. The energy and angular differential ionization yields reveal the signatures of both mechanisms, as well as the role of electron correlation in both the single and double ionization continua. In contrast with previous results on the helium atom, the presence of an electronic core strongly affects the final state leading to back-to-back electron emission even in the a priori less correlated two-photon sequential mechanism. In particular, a dominant pathway via excitation ionization through the ${\mathrm{Be}}^{+}(2p)$ determines the profiles and pulse-duration dependencies of the energy and angle differential yields.We investigate the two-photon double ionization of beryllium atom induced by ultrashort pulses. We use a time-dependent formalism to evaluate the ionization amplitudes and generalized cross sections for the ejection of the $2{s}^{2}$ valence shell electrons in the presence of a fully occupied $1{s}^{2}$ frozen core shell. The relative contributions of the two-photon direct and sequential process are systematically explored by varying both pulse duration and central frequency. The energy and angular differential ionization yields reveal the signatures of both mechanisms, as well as the role of electron correlation in both the single and double ionization continua. In contrast with previous results on the helium atom, the presence of an electronic core strongly affects the final state leading to back-to-back electron emission even in the a priori less correlated two-photon sequential mechanism. In particular, a dominant pathway via excitation ionization through the ${\mathrm{Be}}^{+}(2p)$ determines the profiles and pulse-duration dependencies of the energy and angle differential yields.

Physical Review ANov 5, 20159 citations

FROM MULTIPHOTON TO TUNNEL IONIZATION

S. L. Chin

Advances in multi-photon processes and spectroscopySep 1, 200453 citations

Tracking Quantum Populations in Non-Sequential Double Ionization of Atoms

Stan Haan, Christian Woolley, K. N. Shomsky

Bulletin of the American Physical SocietyJun 6, 20120 citations

2{s}^{2}

valence shell electrons in the presence of a fully occupied

1{s}^{2}

frozen core shell. The relative contributions of the two-photon direct and sequential process are systematically explored by varying both pulse duration and central frequency. The energy and angular differential ionization yields reveal the signatures of both mechanisms, as well as the role of electron correlation in both the single and double ionization continua. In contrast with previous results on the helium atom, the presence of an electronic core strongly affects the final state leading to back-to-back electron emission even in the a priori less correlated two-photon sequential mechanism. In particular, a dominant pathway via excitation ionization through the

{\mathrm{Be}}^{+}(2p)

determines the profiles and pulse-duration dependencies of the energy and angle differential yields.