We present the results of our study on coherent control of photoionization of atomic barium. Our study focused on the understanding of the controllability, especially due to the effect of the coherent interaction between the atomic system and the laser field. The first half of the study investigates the mechanisms of the control behind the previously observed laser phase-insensitive product state control. The controllability of this excitation scheme, two-color two-photon resonantly enhanced excitation, was analyzed from two aspects, the role of ac Stark shift introduced by the strong laser field and the multi-pathway quantum mechanical interferences. We have analyzed the excitation scheme from the analysis of the photoelectron angular distribution measured using the excitation scheme and the monitoring of the intermediate state population. Analysis of the data as well as the numerical simulation showed clear understanding of the role of two mechanisms in the product state control reported. We also investigated the control of the phase lag during the product state control. We conducted the control of the phase lag in the study of asymmetric photoelectron angular distribution, which arises from the concurrent even-odd parity outgoing electron wave excitation. The phase lag was controlled in full range, 2π, and the results were analyzed in terms of the role of autoionizing resonance structures as well as the nature of outgoing electron waves at different locations of the autoionizing resonances.We present the results of our study on coherent control of photoionization of atomic barium. Our study focused on the understanding of the controllability, especially due to the effect of the coherent interaction between the atomic system and the laser field. The first half of the study investigates the mechanisms of the control behind the previously observed laser phase-insensitive product state control. The controllability of this excitation scheme, two-color two-photon resonantly enhanced excitation, was analyzed from two aspects, the role of ac Stark shift introduced by the strong laser field and the multi-pathway quantum mechanical interferences. We have analyzed the excitation scheme from the analysis of the photoelectron angular distribution measured using the excitation scheme and the monitoring of the intermediate state population. Analysis of the data as well as the numerical simulation showed clear understanding of the role of two mechanisms in the product state control reported. We also investigated the control of the phase lag during the product state control. We conducted the control of the phase lag in the study of asymmetric photoelectron angular distribution, which arises from the concurrent even-odd parity outgoing electron wave excitation. The phase lag was controlled in full range, 2π, and the results were analyzed in terms of the role of autoionizing resonance structures as well as the nature of outgoing electron waves at different locations of the autoionizing resonances.

Jan 1, 20060 citations

Coherent one- and two-photon ionization of excited barium

John R. Tolsma, Chris H. Greene

APSMay 1, 20080 citations

Coherent Control Of Photoion Product States

Feng Wang, Ce Chen, Daniel S. Elliott

Quantum Electronics and Laser Science ConferenceMay 18, 19970 citations

Coherent control in atoms, molecules, and semiconductors : proceedings of an international workshop held in Chicago, USA, 19-22 May 1998

W. Pötz, W. Andreas Schroeder

Preface. Part I: Atomic and Molecular systems. Scenarios in Coherent Control P. Brumer, M. Shapiro. Quantum Control in Atomic Systems D. Charalambidis, et al. Laser-phase-sensitive Coherent Control of Photoion Product States in 2-Photon vs. 2-Photon Ionization of Atomic Barium, F. Wang, et al. Coherent Phase control of Photoionization and Photodissociation R.J. Gordon, et al. Coherent Control of Atomic Photoionization and Autoionization P. Lambropoulos, T. Nakajima. Lasing Without Inversion via Interference of Double-Dark Resonances in Atomic and Quantum Well Systems M.O. Scully, et al. Part II: Coherent Control in Semiconductors. Coherence Control of Free Carriers in Bulk Semiconductors H.M. van Driel, et al. Coherent Control of 2D Excitons Probed by Time-Resolved Secondary Emission X. Marie, et al. Many-Body Effects in the Ultrafast Population Transfer in p-Doped Semiconductor Quantum Wells R. Binder, M. Lindberg. Coherent Control of Heavy-Light Hole and Phonon Quantum Beats T. Kuhn, et al. Coherent Control Schemes in Semiconductor Double Wells X. Hu, W. Poetz. Terahertz-Control of Charge-Carrier Wavepackets in Semiconductor Quantum Wells S. Hughes, D.S. Citrin. Microcavity Exciton-Polariton H. Cao. Part III: Coherent Phenomena and Related Topics. Coherent Control of Quantum Localization M. Holthaus. Tunneling of Low-Energetic Electrons in the Presence of Intense Laser Fields: The Formation of Dynamical Barrier States M. Wagner. Hopping Mechanism of Coherent Photovoltaic Effect and Photoinduced Polar Anisotropy in Glass E.M. Baskin, M.V. Entin. Heterodyning Scheme Employing Quantum Interference J.B. Khurgin, et al. Generation of Widely Tunable THz-Wave Using Nonlinear Optics K. Kawase, H.Ito. List of Participants.Preface. Part I: Atomic and Molecular systems. Scenarios in Coherent Control P. Brumer, M. Shapiro. Quantum Control in Atomic Systems D. Charalambidis, et al. Laser-phase-sensitive Coherent Control of Photoion Product States in 2-Photon vs. 2-Photon Ionization of Atomic Barium, F. Wang, et al. Coherent Phase control of Photoionization and Photodissociation R.J. Gordon, et al. Coherent Control of Atomic Photoionization and Autoionization P. Lambropoulos, T. Nakajima. Lasing Without Inversion via Interference of Double-Dark Resonances in Atomic and Quantum Well Systems M.O. Scully, et al. Part II: Coherent Control in Semiconductors. Coherence Control of Free Carriers in Bulk Semiconductors H.M. van Driel, et al. Coherent Control of 2D Excitons Probed by Time-Resolved Secondary Emission X. Marie, et al. Many-Body Effects in the Ultrafast Population Transfer in p-Doped Semiconductor Quantum Wells R. Binder, M. Lindberg. Coherent Control of Heavy-Light Hole and Phonon Quantum Beats T. Kuhn, et al. Coherent Control Schemes in Semiconductor Double Wells X. Hu, W. Poetz. Terahertz-Control of Charge-Carrier Wavepackets in Semiconductor Quantum Wells S. Hughes, D.S. Citrin. Microcavity Exciton-Polariton H. Cao. Part III: Coherent Phenomena and Related Topics. Coherent Control of Quantum Localization M. Holthaus. Tunneling of Low-Energetic Electrons in the Presence of Intense Laser Fields: The Formation of Dynamical Barrier States M. Wagner. Hopping Mechanism of Coherent Photovoltaic Effect and Photoinduced Polar Anisotropy in Glass E.M. Baskin, M.V. Entin. Heterodyning Scheme Employing Quantum Interference J.B. Khurgin, et al. Generation of Widely Tunable THz-Wave Using Nonlinear Optics K. Kawase, H.Ito. List of Participants.

Kluwer eBooksJan 1, 19992 citations

One- and two-photon ionization cross sections of the laser-excited 6s6p P11 state of barium

John R. Tolsma, Daniel J. Haxton, Chris H. Greene +2 more

Stimulated by a recent measurement of coherent control in photoionization of atomic barium, we have calculated one- and two-photon ionization cross sections of the aligned $6s6p\text{ }{^{1}P}_{1}$ state of barium in the energy range between the $5{d}_{3/2}$ and $5{d}_{5/2}$ states of ${\text{Ba}}^{+}$ . We have also measured these photoionization spectra in the same energy region, driving the one- or two-photon processes with the second or first harmonic of a tunable dye laser, respectively. Our calculations employ the eigenchannel $R$ -matrix method and multichannel quantum defect theory to calculate the rich array of autoionizing resonances in this energy range. The nonresonant two-photon process is described using lowest-order perturbation theory for the photon-atom interactions, with a discretized intermediate-state one-electron continuum. The calculations provide an absolute normalization for the experiment, and they accurately reproduce the rich resonance structures in both the one- and two-photon cross sections, and confirm other aspects of the experimental observations. These results demonstrate the ability of these computationally inexpensive methods to reproduce experimental observables in one- and two-photon ionization of heavy alkaline earths, and they lay the groundwork for future studies of the phase-controlled interference between one- and two-photon ionization processes.Stimulated by a recent measurement of coherent control in photoionization of atomic barium, we have calculated one- and two-photon ionization cross sections of the aligned $6s6p\text{ }{^{1}P}_{1}$ state of barium in the energy range between the $5{d}_{3/2}$ and $5{d}_{5/2}$ states of ${\text{Ba}}^{+}$. We have also measured these photoionization spectra in the same energy region, driving the one- or two-photon processes with the second or first harmonic of a tunable dye laser, respectively. Our calculations employ the eigenchannel $R$-matrix method and multichannel quantum defect theory to calculate the rich array of autoionizing resonances in this energy range. The nonresonant two-photon process is described using lowest-order perturbation theory for the photon-atom interactions, with a discretized intermediate-state one-electron continuum. The calculations provide an absolute normalization for the experiment, and they accurately reproduce the rich resonance structures in both the one- and two-photon cross sections, and confirm other aspects of the experimental observations. These results demonstrate the ability of these computationally inexpensive methods to reproduce experimental observables in one- and two-photon ionization of heavy alkaline earths, and they lay the groundwork for future studies of the phase-controlled interference between one- and two-photon ionization processes.

arXiv:0906.1638Physical Review ASep 1, 20099 citations

Quantum control of atomic two-photon ionization by ultrashort light pulse effect

Han Chieh Lee, Shih-Da Jheng, Tsin Fu Jiang

The European Physical Journal DJul 1, 20170 citations

Stimulated by a recent measurement of coherent control in photoionization of atomic barium, we have calculated one- and two-photon ionization cross sections of the aligned

6s6p\text{ }{^{1}P}_{1}

state of barium in the energy range between the

5{d}_{3/2}

and

5{d}_{5/2}

states of

{\text{Ba}}^{+}

. We have also measured these photoionization spectra in the same energy region, driving the one- or two-photon processes with the second or first harmonic of a tunable dye laser, respectively. Our calculations employ the eigenchannel

R

-matrix method and multichannel quantum defect theory to calculate the rich array of autoionizing resonances in this energy range. The nonresonant two-photon process is described using lowest-order perturbation theory for the photon-atom interactions, with a discretized intermediate-state one-electron continuum. The calculations provide an absolute normalization for the experiment, and they accurately reproduce the rich resonance structures in both the one- and two-photon cross sections, and confirm other aspects of the experimental observations. These results demonstrate the ability of these computationally inexpensive methods to reproduce experimental observables in one- and two-photon ionization of heavy alkaline earths, and they lay the groundwork for future studies of the phase-controlled interference between one- and two-photon ionization processes.