Coherent Control of Resonance-Mediated Reactions: F + HD

Two-photon photoassociation of hot magnesium atoms by femtosecond laser pulses, creating electronically excited magnesium dimer molecules, is studied from first principles, combining ab initio quantum chemistry and molecular quantum dynamics. This theoretical framework allows for rationalizing the generation of molecular rovibrational coherence from thermally hot atoms [L. Rybak et al., Phys. Rev. Lett. 107, 273001 (2011)]. Random phase thermal wave functions are employed to model the thermal ensemble of hot colliding atoms. Comparing two different choices of basis functions, random phase wavefunctions built from eigenstates are found to have the fastest convergence for the photoassociation yield. The interaction of the colliding atoms with a femtosecond laser pulse is modeled non-perturbatively to account for strong-field effects.

“…19 For a binary reaction, the nature of the scattering continuum is mainly determined by the temperature of the reactants. As temperature decreases, higher partial waves are frozen out.…”

Section: Introductionmentioning

confidence: 99%

Femtosecond two-photon photoassociation of hot magnesium atoms: A quantum dynamical study using thermal random phase wavefunctions

Amaran

Kosloff

Tomza

et al. 2013

“…Laser catalysis of chemical reactions has been discussed [232][233][234][235][236] and multi-photon ionization of atoms and molecules in intense laser fields continues to be an active area of research. Orientation of molecules in strong electric fields has been explored and how steric effects influence reactions in external fields has been investigated.…”

Section: F External Field Effects On Reactivitymentioning

confidence: 99%

Perspective: Ultracold molecules and the dawn of cold controlled chemistry

Balakrishnan

2016

291

271

Ultracold molecules offer unprecedented opportunities for the controlled interrogation of molecular events, including chemical reactivity in the ultimate quantum regime. The proliferation of methods to create, cool, and confine them has allowed the investigation of a diverse array of molecular systems and chemical reactions at temperatures where only a single partial wave contributes. Here we present a brief account of recent progress on the experimental and theoretical fronts on cold and ultracold molecules and the opportunities and challenges they provide for a fundamental understanding of bimolecular chemical reaction dynamics. Published by AIP Publishing. [http://dx

“…70 The integral cross sections in the neighborhood of these features have been shown to be a prototypical example for obtaining quantum coherent control in collision processes. 71 However, studies of the stereodynamics and of its relationship with the reaction mechanisms are relatively scarce 34,72 and mainly performed using the Stark and Werner (SW) PES 73 or its spin-orbit corrected variants. 74 A deep quantum stereodynamical analysis of the HF(v = 2) channel in the range of energies of the resonance feature mentioned above using SW PES has been recently reported.…”

Section: F + Hd Chemical Reactionmentioning

confidence: 99%

Polarization of molecular angular momentum in the chemical reactions Li + HF and F + HD

Krasilnikov

Popov

Roncero

et al. 2013

The quantum mechanical approach to vector correlation of angular momentum orientation and alignment in chemical reactions [G. Balint- (2011)] reactions for which accurate scattering information has become recently available through time-dependent and time-independent approaches. Application of the theory to two important particular cases of the reactive collisions has been considered: (i) the influence of the angular momentum polarization of reactants in the entrance channel on the spatial distribution of the products in the exit channel and (ii) angular momentum polarization of the products of the reaction between unpolarized reactants. In the former case, the role of the angular momentum alignment of the reactants is shown to be large, particularly when the angular momentum is perpendicular to the reaction scattering plane. In the latter case, the orientation and alignment of the product angular momentum was found to be significant and strongly dependent on the scattering angle. The calculation also reveals significant differences between the vector correlation properties of the two reactions under study which are due to difference in the reaction mechanisms. In the case of F + HD reaction, the branching ratio between HF and DF production points out interest in the insight gained into the detailed dynamics, when information is available either from exact quantum mechanical calculations or from especially designed experiments. Also, the geometrical arrangement for the experimental determination of the product angular momentum orientation and alignment based on a compact and convenient spherical tensor expression for the intensity of the resonance enhanced multiphoton ionization (REMPI 2 + 1) signal is suggested. © 2013 AIP Publishing LLC.