Rovibrational laser control targeting a dark state in acetylene. Simulation in the <i>N</i><i>_s</i> = 1, N<i>_r</i> = 5 polyad

Optimal control theory in the Liouville space is used to perform rovibrational control by means of a laser pulse in a polyad of acetylene in order to populate a dark vibrational state. The initial mixed state is a truncated Boltzmann distribution of rotational levels from <i>J</i>=27 to <i>J</i>=31 of the ground vibrational state. The target state is a rotational equidistribution of levels ranging from <i>J</i>=28 to <i>J</i>=32 of the first excited vibrational dark state including quanta of energy in each bending modes, with positive vibrational angular momenta. The simulation is performed by using a manifold of eigenstates of a full-dimensional Hamiltonian calibrated by high precision spectroscopy known as the global acetylene Hamiltonian [B. Amyay <i>et al.</i>, J. Chem. Phys. <b>131</b>, 114301 (2009)]. The control is successful as an Uhlmann's fidelity of 0.98 is reached.