Control in a dissipative environment: the example of a Cope rearrangement

in Journal of Physical Chemistry A (2012), 116

Quantum gates driven by microwave pulses in hyperfine levels of ultracold heteronuclear dimers

in European Physical Journal D -- Atoms, Molecules, Clusters & Optical Physics (2011), 64

Local control of non-adiabatic dissociation dynamics

in Journal of Chemical Physics (2011), 134

Ab initio calculation of H + He+ charge-transfer cross section for plasma physics

in Physical Review. A (2010), 82

Quantum dynamics of the charge transfer in C+ + S at low collision energy

in Journal of Physics : B Atomic Molecular & Optical Physics (2010), 43

Photodissociation of the HeH+ ion into excited fragments (n=2,3) by time-dependent methods

in Physical Review. A (2009), 2009(80), 033417

Optimal control simulation of the Deutsch-Josza algorithm in a two-dimensional double well coupled to an environment

in Journal of Chemical Physics (2007), 126

Laser control in a bifurcating region

in Physical Review. A (2006), 74(4), 0434191-14

We present a complete analysis of the laser control of a model molecular system using both optimal control theory and adiabatic techniques. This molecule has a particular potential energy surface with a ... [more ▼]

We present a complete analysis of the laser control of a model molecular system using both optimal control theory and adiabatic techniques. This molecule has a particular potential energy surface with a bifurcating region connecting three potential wells which allows a variety of processes such as isomerization, tunneling, or implementation of quantum gates on one or two qubits. The parameters of the model have been chosen so as to reproduce the main features of H3CO which is a molecule benchmark for such dynamics. We show the feasibility of different processes and we investigate their robustness against variations of laser field. We discuss the conditions under which each method of control gives the best results. We also point out the relation between optimal control theory and local control. [less ▲]

Wave packets in a bifurcating region of an energy landscape: Diels-Alder dimerization of cyclopentadiene

in Journal of Chemical Physics (2005), 122(18), 1843041-10

Quantum dynamics in a valley ridge inflection (VRI) point region is analyzed in the case of the Diels-Alder endo-dimerization of cyclopentadiene pointed out recently by [Caramella , J. Am. Chem. Soc. 124 ... [more ▼]

Quantum dynamics in a valley ridge inflection (VRI) point region is analyzed in the case of the Diels-Alder endo-dimerization of cyclopentadiene pointed out recently by [Caramella , J. Am. Chem. Soc. 124, 1130 (2002)]. The VRI point is located along the reaction path connecting the bispericyclic symmetrical transition structure put in evidence by Caramella and the transition state of the Cope rearrangement. Dynamics is carried out by using constrained Hamiltonian methodology. The active coordinates are the first formed C-C bond length and the difference between the two other C-C bond lengths which achieve the dimerization as 4+2 or 2+4 adducts. A two-dimensional (2D) minimum-energy surface have been computed at the Becke 3 Lee-Yong-Parr/6-31G(*) level. The energy landscape can be classified as an uphill ridge-pitchfork VRI bifurcation according to a recent classification of bifurcation events [W. Quapp, J. Mol. Struct. 695-696, 95 (2004)]. Dynamics does not describe the thermal reaction but concerns wave packets which could be prepared by pulse reagents, i.e., by coherent control. We analyze how the shape and initial location on the ground potential-energy surface are linked to the synchronous or asynchronous mechanism of the final step after the first transition state. We use a one-dimensional model of optimum control theory to check the feasibility of such a coherent preparation. The wave-packet evolution in the VRI domain is well explained by semiclassical predictions even with the negative curvature of the unstable ridge. Finally, a crude model of dissipation has been introduced to test the stability of the 2D predictions. (c) 2005 American Institute of Physics. [less ▲]

Cumulative isomerization probability by various transition state wave packet methods including the MCTDH algorithm

in Journal of Chemical Physics (2004), 121