## Dynamics and control of open quantum systems: Charge transfer at an heterojunction and control of an isomerization

A. Chenel^{†}, C. Meier^{§},M. Desouter-Lecomte^{†}

^{†}Laboratoire de Chimie Physique, Université Paris-Sud, 91405 Orsay, France.

^{†} LCAR-IRSAMC, Université Paul Sabatier, 31062 Toulouse, France.

Mardi 25 Mars 2014, 14^{h}00

bibliothèque LCT, tour 12 - 13, 4e étage

The tudy of quantum effects as quantum coherences and their exploitation for control by laser pulse is still a numerical challenge in big systems. To reduce the dimensionality of the problem, dissipative dynamics focuses on a quantum subspace that is coupled to a thermal bath made of harmonic oscillators. The essential tool is the spectral density of the bath, that contains all the information about the bath.

Several strategies coexist and complement one another. We adopt a non-markovian master equation for the evolution of the density matrix associated to the quantum system. This approach, proposed by Meier and Tannor^{[1]}, is perturbative in the system-bath coupling, but not in the interaction with a laser field. Our goal is to confront this methodology to systems calibrated by *ab initio* calculations.

We first study the ultrafast electron transfer modelling an oligothiophene-fullerene junction, found in organic photovoltaic cells. We present a way of overcoming the limitation of the perturbative regime, using the Brownian oscillator representation of the spin-boson model^{[2]}.
Then we combine the quantum dynamical method described above with the optimal control theory (OCT) method. An application is the control of an isomerization, the Cope rearrangement, in the context of Diels-Alder reactions.

We show that including the dissipation at the design stage of the field enables the control algorithm to react on the environment-induced decoherence and to lead to a better yield^{[3,4]}.

[1] C. Meier, D.J. Tannor, *J. Chem. Phys.* 111, 3365 (1999)

[2] A. Chenel, E. Mangaud, I. Burghardt, C. Meier and M. Desouter-Lecomte, *J. Chem. Phys.* 140, 044104 (2014)

[3] A. Chenel, G. Dive, C. Meier and M. Desouter-Lecomte, *J. Phys. Chem. A* 116, 11273 (2012)

[4] G. Dive, R. Robiette, A. Chenel, M. Ndong, C. Meier and M. Desouter-Lecomte, *Theor. Chem. Acc.* 131, 1236 (2012)