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Full-Text Articles in Physics
Nondipole Effects In Double Photoionization Of He, A.Y. Istomin, N. L. Manakov, A. V. Meremianin, Anthony F. Starace
Nondipole Effects In Double Photoionization Of He, A.Y. Istomin, N. L. Manakov, A. V. Meremianin, Anthony F. Starace
Anthony F. Starace Publications
Lowest-order nondipole effects are studied in double photoionization (DPI) of the He atom. Ah initio parametrizations of the quadrupole transition amplitude for DPI from the 1S0state are presented in terms of the exact two-electron reduced matrix elements. Parametrizations for the dipole-quadrupole triply differential cross section (TDCS) and doubly differential cross section (DDCS) are presented in terms of polarization-independent amplitudes for the case of an elliptically polarized photon. Expressions for the DDCS in terms of the reduced two-electron matrix elements are also given. A general analysis of retardation-induced asymmetries of the TDCS including the circular dichroism effect at …
Threshold Effects In Strong-Field Detachment Of H- And F-: Plateau Enhancements And Angular Distribution Variations, Katarzyna Krajewska, Ilya I. Fabrikant, Anthony F. Starace
Threshold Effects In Strong-Field Detachment Of H- And F-: Plateau Enhancements And Angular Distribution Variations, Katarzyna Krajewska, Ilya I. Fabrikant, Anthony F. Starace
Anthony F. Starace Publications
Above-threshold detachment (ATD) rates for H1 and F1 ions in the high-energy plateau region are calculated as functions of photon number and laser intensity by solving the time-dependent Schrödinger equation within the Sturmian-Floquet approach. Pronounced enhancements of the ATD rates are found (up to an order of magnitude) as the laser-field intensity passes across ponderomotive-potential-induced channel closings. We confirm the zero-range potential model results of Borca et al. [Phys. Rev. Lett. 88, 193001 (2002)] for negative ions whose initial states have s symmetry, and we investigate here the case of initial states having p symmetry. Depending on …
Application Of Coulomb Wave Function Discrete Variable Representation To Atomic Systems In Strong Laser Fields, Liang-You Peng, Anthony F. Starace
Application Of Coulomb Wave Function Discrete Variable Representation To Atomic Systems In Strong Laser Fields, Liang-You Peng, Anthony F. Starace
Anthony F. Starace Publications
We present an efficient and accurate grid method for solving the time-dependent Schrödinger equation for an atomic system interacting with an intense laser pulse. Instead of the usual finite difference (FD) method, the radial coordinate is discretized using the discrete variable representation (DVR) constructed from Coulomb wave functions. For an accurate description of the ionization dynamics of atomic systems, the Coulomb wave function discrete variable representation (CWDVR) method needs three to ten times fewer grid points than the FD method. The resultant grid points of the CWDVR are distributed unevenly so that one has a finer grid near the origin …
Elliptic And Circular Dichroism Effects In Two-Photon Double Ionization Of Atoms, Andrei Y. Istomin, Evgeny Pronin, N. L. Manakov, S.I. Marmo, Anthony F. Starace
Elliptic And Circular Dichroism Effects In Two-Photon Double Ionization Of Atoms, Andrei Y. Istomin, Evgeny Pronin, N. L. Manakov, S.I. Marmo, Anthony F. Starace
Anthony F. Starace Publications
An ab initio parametrization of the two-photon double ionization amplitude from an s2 subshell of an atom in a 1S state is presented and used to predict two light polarization effects on photoelectron angular distributions that do not exist in single-photon double ionization: (i) elliptic dichroism and (ii) circular dichroism at equal energy sharing. Estimates for He show large magnitudes for these effects, which provide a means for polarization control of double ionization by vacuum ultraviolet light.
Entanglement Evolution In The Presence Of Decoherence, Jin Wang, Herman Batelaan, Jeremy Podany, Anthony F. Starace
Entanglement Evolution In The Presence Of Decoherence, Jin Wang, Herman Batelaan, Jeremy Podany, Anthony F. Starace
Anthony F. Starace Publications
The entanglement of two qubits, each defined as an effective two-level, spin 1/2 system, is investigated for the case that the qubits interact via a Heisenberg XY interaction and are subject to decoherence due to population relaxation and thermal effects. For zero temperature, the time dependent concurrence is studied analytically and numerically for some typical initial states, including a separable (unentangled) initial state. An analytical formula for non-zero steady state concurrence is found for any initial state, and optimal parameter values for maximizing steady state concurrence are given. The steady state concurrence is found analytically to remain non-zero for low, …
Photodetachment Of H- By A Short Laser Pulse In Crossed Static Electric And Magnetic Fields, Liang-You Peng, Qiaoling Wang, Anthony F. Starace
Photodetachment Of H- By A Short Laser Pulse In Crossed Static Electric And Magnetic Fields, Liang-You Peng, Qiaoling Wang, Anthony F. Starace
Anthony F. Starace Publications
We present a detailed quantum mechanical treatment of the photodetachment of H- by a short laser pulse in the presence of crossed static electric and magnetic fields. An exact analytic formula is presented for the final state electron wave function (describing an electron in both static electric and magnetic fields and a short laser pulse of arbitrary intensity). In the limit of a weak laser pulse, final state electron wave packet motion is examined and related to the closed classical electron orbits in crossed static fields predicted by Peters and Delos [Phys. Rev. A 47, 3020 (1993)]. Owing to …
An Analytical Quantum Model For Intense Field Processes: Quantum Origin Of Rescattering Plateaus, M. V. Frolov, A. A. Khuskivadze, N. L. Manakov, Anthony F. Starace
An Analytical Quantum Model For Intense Field Processes: Quantum Origin Of Rescattering Plateaus, M. V. Frolov, A. A. Khuskivadze, N. L. Manakov, Anthony F. Starace
Anthony F. Starace Publications
After a brief comparison of two basic quantum approaches for the analytic treatment of strong laser field phenomena, we analyze the spatial and temporal dependences of the quasistationary, quasienergy state wavefunction Φε(r,t) of a weakly bound level in a strong laser field. We find from this analysis that the characteristic high-energy plateau structures in the spectra of laser– atom processes originate from similar plateau features in the spectra of the Fourier-harmonic components, Φn(r), of Φε(r,t). Together with a quantum interpretation of the well-known rescattering scenario in terms of these wavefunctions, the results of this …
Laser Acceleration Of Electrons To Giga-Electron-Volt Energies Using Highly Charged Ions, S.X. Hu, Anthony F. Starace
Laser Acceleration Of Electrons To Giga-Electron-Volt Energies Using Highly Charged Ions, S.X. Hu, Anthony F. Starace
Anthony F. Starace Publications
The recent proposal to use highly charged ions as sources of electrons for laser acceleration [S. X. Hu and A. F. Starace, Phys. Rev. Lett. 88, 245003 (2002)] is investigated here in detail by means of three-dimensional, relativistic Monte Carlo simulations for a variety of system parameters, such as laser pulse duration, ionic charge state, and laser focusing spot size. Realistic laser focusing effects—e.g., the existence of longitudinal laser field components—are taken into account. Results of spatial averaging over the laser focus are also presented. These numerical simulations show that the proposed scheme for laser acceleration of electrons from highly …
Nondipole Effects In Double Photoionization Of He At 450 Ev Excess Energy, Andrei Y. Istomin, Anthony F. Starace, N.L. Manakov, A.V. Meremianin, A. S. Kheifets, Igor Bray
Nondipole Effects In Double Photoionization Of He At 450 Ev Excess Energy, Andrei Y. Istomin, Anthony F. Starace, N.L. Manakov, A.V. Meremianin, A. S. Kheifets, Igor Bray
Anthony F. Starace Publications
Convergent close-coupling results for the triply differential cross section for double photoionization of He that include dipole–quadrupole terms are shown to have improved agreement (as compared to dipole approximation results) with recent experiments using linearly polarized light (Knapp A et al 2005 J. Phys. B: At. Mol. Opt. Phys. 38 615) for a number of kinematical configurations.