The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
P B Corkum - One of the best experts on this subject based on the ideXlab platform.
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stopping a vibrational wave packet with laser Induced Dipole forces
Physical Review Letters, 2004Co-Authors: Hiromichi Niikura, D M Villeneuve, P B CorkumAbstract:Intense near-infrared laser pulses can generate laser-Induced Dipole forces that are strong enough to influence or control vibrational motion of a small molecule. Generally, the force acts to pull the molecule apart. Our numerical simulations show that, by applying the laser-Induced Dipole force at an appropriate time within one vibrational period, the wave packet motion of $\mathrm{H}_{2}{}^{+}$ or $\mathrm{D}_{2}{}^{+}$ can be accelerated or decelerated. Using the wave packet formed by the rapid ionization of ${\mathrm{H}}_{2}$ or ${\mathrm{D}}_{2}$, we also show that it is possible to move the vibrational population almost entirely to the $v=0$ state. Coherent cooling of the molecular vibrational motion can be achieved.
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internal laser Induced Dipole force at work in c60 molecule
Physical Review Letters, 2003Co-Authors: V R Bhardwaj, P B Corkum, D M RaynerAbstract:We show how the many electron response of a complex molecule to an intense laser field can be incorporated with the single active electron picture. This enables us to introduce an ``over-the-barrier'' model for ${\mathrm{C}}_{60}^{z+}$ ionization, valid for long wavelength light. Using infrared radiation, we confirm the model and also produce stable, highly charged ${\mathrm{C}}_{60}$ reaching ${\mathrm{C}}_{60}^{12+}$, the highest charge state ever observed. At high intensities and high charge states the internal laser-Induced Dipole force and rapid charging lead to stress on the molecule. The interplay between the forces provides control and suggest strategies for reaching even higher charge states.
Lothar Frommhold - One of the best experts on this subject based on the ideXlab platform.
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interacting he and ar atoms revised theoretical interaction potential Dipole moment and collision Induced absorption spectra
Journal of Chemical Physics, 2015Co-Authors: Wilfried Meyer, Lothar FrommholdAbstract:Coupled cluster quantum chemical calculations of the potential energy surface and the Induced Dipole surface are reported for the He–Ar van der Waals collisional complex. Spectroscopic parameters are derived from global analytical fits while an accurate value for the long-range Dipole coefficient D7 is obtained by perturbation methods. Collision-Induced absorption spectra are computed quantum mechanically and compared with existing measurements.
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Ab initio Interaction-Induced Dipoles and Related Absorption Spectra
Collision- and Interaction-Induced Spectroscopy, 1995Co-Authors: Wilfried Meyer, Lothar FrommholdAbstract:The interaction-Induced Dipole moments of pairs like H-He, He-Ar, H2-He, H2-Ar, and H2-H2 have been calculated by treating the complex of the two molecules as a supermolecule in the self-consistent-field and size-consistent, coupled-electron pair approximations as well as by the multi-reference-configuration-interaction method. Whenever H2 is involved, rotovibrational matrix elements of the Induced Dipole components are calculated and used as input for the line shape calculations of rototranslational, fundamental and first overtone Induced absorption bands of H2. For comparison with spectroscopic measurements, we also compute interaction-Induced absorption line shapes, taking into account the dependences of the interaction potential on vibrational excitation. Measured and calculated spectra are found to be in close agreement, even in the far wings.
D M Rayner - One of the best experts on this subject based on the ideXlab platform.
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internal laser Induced Dipole force at work in c60 molecule
Physical Review Letters, 2003Co-Authors: V R Bhardwaj, P B Corkum, D M RaynerAbstract:We show how the many electron response of a complex molecule to an intense laser field can be incorporated with the single active electron picture. This enables us to introduce an ``over-the-barrier'' model for ${\mathrm{C}}_{60}^{z+}$ ionization, valid for long wavelength light. Using infrared radiation, we confirm the model and also produce stable, highly charged ${\mathrm{C}}_{60}$ reaching ${\mathrm{C}}_{60}^{12+}$, the highest charge state ever observed. At high intensities and high charge states the internal laser-Induced Dipole force and rapid charging lead to stress on the molecule. The interplay between the forces provides control and suggest strategies for reaching even higher charge states.
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Internal Laser-Induced Dipole Force at Work in C 60 Molecule
Physical Review Letters, 2003Co-Authors: V R Bhardwaj, Paul B. Corkum, D M RaynerAbstract:We show how the many electron response of a complex molecule to an intense laser field can be incorporated with the single active electron picture. This enables us to introduce an ``over-the-barrier'' model for ${\mathrm{C}}_{60}^{z+}$ ionization, valid for long wavelength light. Using infrared radiation, we confirm the model and also produce stable, highly charged ${\mathrm{C}}_{60}$ reaching ${\mathrm{C}}_{60}^{12+}$, the highest charge state ever observed. At high intensities and high charge states the internal laser-Induced Dipole force and rapid charging lead to stress on the molecule. The interplay between the forces provides control and suggest strategies for reaching even higher charge states.
Daniil N Chistikov - One of the best experts on this subject based on the ideXlab platform.
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simulation of collision Induced absorption spectra based on classical trajectories and ab initio potential and Induced Dipole surfaces i case study of n2 n2 rototranslational band
Journal of Chemical Physics, 2019Co-Authors: Daniil N Chistikov, Artem A Finenko, S E Lokshtanov, Sergey V Petrov, A A VigasinAbstract:This paper presents theoretical formalism and some results of the collision-Induced absorption (CIA) spectral simulation based on the classical trajectory analysis. Our consideration relies on the use of ab initio potential energy and Dipole moment surfaces for two interacting rigid monomers. Rigorous intermolecular Hamiltonian is represented and used in the body-fixed reference frame. The complete set of dynamical equations with Boltzmann-weighted initial conditions is solved to render a large number of classical trajectories. The spectral shape is calculated as an ensemble-averaged Fourier spectrum issued from the time-dependent Induced Dipole along individual scattering trajectories. Considering a pair of N2 molecules as an example, we have calculated the rototranslational CIA band profiles at T = 78, 89, 109, 129, 149, 179, 228, 300, and 343 K. The classical trajectory-based spectral shape was corrected to satisfy the quantum principle of detailed balance. Good accuracy of our semiclassical approach was demonstrated by comparison with available experimental data as well as with results of the previously published purely quantum simulation by Karman et al. [J. Chem. Phys. 142, 084306 (2015)] in which the same ab initio calculated N2–N2 potential energy and Induced Dipole moment surfaces were used.This paper presents theoretical formalism and some results of the collision-Induced absorption (CIA) spectral simulation based on the classical trajectory analysis. Our consideration relies on the use of ab initio potential energy and Dipole moment surfaces for two interacting rigid monomers. Rigorous intermolecular Hamiltonian is represented and used in the body-fixed reference frame. The complete set of dynamical equations with Boltzmann-weighted initial conditions is solved to render a large number of classical trajectories. The spectral shape is calculated as an ensemble-averaged Fourier spectrum issued from the time-dependent Induced Dipole along individual scattering trajectories. Considering a pair of N2 molecules as an example, we have calculated the rototranslational CIA band profiles at T = 78, 89, 109, 129, 149, 179, 228, 300, and 343 K. The classical trajectory-based spectral shape was corrected to satisfy the quantum principle of detailed balance. Good accuracy of our semiclassical approach w...
Takashi Ando - One of the best experts on this subject based on the ideXlab platform.
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temperature dependent la and al Induced Dipole behavior monitored by femtosecond pump probe photoelectron spectroscopy
Applied Physics Letters, 2010Co-Authors: Hiroaki Arimura, Richard Haight, Stephen Brown, A J Kellock, A Callegari, Matthew Copel, Heiji Watanabe, Vijay Narayanan, Takashi AndoAbstract:The impact of thermal budget on La- and Al-Induced Dipoles is systematically investigated by femtosecond pump/probe photoelectron spectroscopy. We find that the La-Induced Dipole requires annealing at 300 °C for complete activation, whereas the Al-Induced Dipole is activated at the lower temperature but requires annealing at 300 °C to eliminate a counteracting sheet charge. When La and Al atoms coexist on a SiO2 surface, the La-Induced Dipole becomes dominative after a silicate-forming reaction at the temperature above 600 °C. This phenomenon is attributed to the different natures of the La- and Al-Induced Dipoles, i.e., long-range and short-range.
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Temperature-dependent La- and Al-Induced Dipole behavior monitored by femtosecond pump/probe photoelectron spectroscopy
Applied Physics Letters, 2010Co-Authors: Hiroaki Arimura, Richard Haight, Stephen Brown, A J Kellock, A Callegari, Matthew Copel, Heiji Watanabe, Vijay Narayanan, Takashi AndoAbstract:The impact of thermal budget on La- and Al-Induced Dipoles is systematically investigated by femtosecond pump/probe photoelectron spectroscopy. We find that the La-Induced Dipole requires annealing at 300 °C for complete activation, whereas the Al-Induced Dipole is activated at the lower temperature but requires annealing at 300 °C to eliminate a counteracting sheet charge. When La and Al atoms coexist on a SiO2 surface, the La-Induced Dipole becomes dominative after a silicate-forming reaction at the temperature above 600 °C. This phenomenon is attributed to the different natures of the La- and Al-Induced Dipoles, i.e., long-range and short-range.
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Physical origins of mobility degradation in extremely scaled SiO2/HfO2 gate stacks with La and Al Induced Dipoles
Applied Physics Letters, 2010Co-Authors: Takashi Ando, Heiji Watanabe, Matt Copel, John Bruley, Martin M. Frank, Vijay NarayananAbstract:We demonstrate metal-gate-Induced interfacial layer (IL) scaling using a HfO2 dielectric and clarify the kinetics underlying this process. The intrinsic IL scaling effect on electron mobility is separated from La and Al-Induced Dipole effects. We find that the mobility degradation for La-containing high-κ dielectrics is not due to the La-Induced Dipole but due to the intrinsic IL scaling effect, whereas the Al-Induced Dipole brings about additional mobility degradation. This unique nature of the La-Induced Dipole enables aggressive equivalent oxide thickness scaling down to 0.42 nm without extrinsic mobility degradation when combined with IL scaling.