Signature of Molecular Orbital Symmetry in High-Order Harmonic Generation by Bichromatic Circularly Polarized Laser Pulses

Abstract

Molecular orbital symmetry is shown to be an important factor in determining orders and helicities (polarizations) of high-order harmonic generation (HHG) by intense femtosecond counter-rotating bichromatic circularly polarized laser pulses. Numerical solutions of time-dependent Schrödinger equations (TDSE) for the one-electron molecular ions H2 + and H3 2+ for different initial electronic states show that harmonic orders and helicities are dependent on orbital symmetries and of the net incident pulse electric field. The numerical results and properties of the harmonics are described by dynamical symmetry theory and time profile analysis of the high-order harmonics, thus confirming that orbital and laser pulse symmetry dependence are generic in HHG of molecules.

Strong Laser Field-Driven Coupled Electron–Nuclear Dynamics: Quantum vs Classical Description

“…It is worth to mention that by employing quasi-classical trajectory methods, the double-ionization channel can be properly counted when the diatomic bond length r bc < 9.5 bohr and the electron energy ε i > 0. Quantum mechanical probabilities of the other three dynamical channels are calculated by using the expressions given in ref . On the other hand, in the case of classical dynamical calculations, a similar method, as described elsewhere for the case of the HD + molecule, has been employed to obtain the reaction probabilities.…”

“…Light–matter interaction based on strong ultrashort laser pulses has opened the door for studying electronic and nuclear dynamics with unprecedented temporal resolution. − Using such light sources, in addition, fine spatial resolution (Angstrom) imaging of electron wave packet in molecules has also been achieved in the recent past. − A wise combination of spatial and temporal imaging provides a way to realize a dream of real-time controlling of fundamental processes in physics, chemistry, and biology. − More recently, with the advent of attosecond science, , it is now possible to probe the electronic dynamics in real time, well separated with the slower nuclear dynamics which is the basis of well-celebrated Born–Oppenheimer approximation. However, in the case of intense laser pulse (intensity >10 13 W/cm 2 ) and in chemical reactions where the longtime dynamics is needed to be observed, the role of nuclear motion, which gets coupled with the electronic motion, becomes utmost important. − Such a complex coupled electron–nuclear dynamics is not yet fully understood because of difficulties in treating different time scales for electron (10 –18 s) and nuclear (10 –15 s) motion, simultaneously.…”

Generating attosecond pulses with controllable polarization from cyclic H32+ molecules by bichromatic circular fields

“…Here, |E (1) and |E (2) are two orthogonal degenerate real states, which can be obtained by the imaginary-time evolution method. [25,28] Similar to the atomic configuration, an electron in |E + orbital (m = +1) circulates in the same sense as the right-handed circularly polarized fields, while the |E − orbital (m = −1) is counterrotating. [29] The electronic density distributions of these three states are shown in Figs.…”

“…[22] In addition, researchers investigated the generation of harmonics from cyclic molecules H q+ n , and (nearly) CP harmonics are obtained. [23][24][25] To the best of our knowledge, the generation of the elliptical APTs using cyclic molecules under a BCCP field, however, has never been realized. In this work, we extend the BCCP scheme to a cyclic molecule target, and investigate polarization of harmonics from H 2+ 3 molecular ions.…”

Quantum model of dynamic Stark‐induced degenerate vibronic state by two nonresonant shift‐up lasers for π‐electron angular momentum generation

“…Laser‐driven π‐electron dynamics in aromatic ring molecules have attracted much interest. [ 1–13 ] In particular, the laser‐driven coherent π‐electron dynamics is expected to play an important role in the laser control of chemical reactions and development of next‐generation organic electronics. [ 14–25 ] Theoretical studies of the laser‐induced π‐electron ring current in high‐symmetry aromatic ring molecules, such as Mg porphyrin, have been initiated by Manz's group.…”