Quantum optimal control strategies for photoisomerization via electronically excited states

Optimal control of the photoisomerization of Li2Na from the stable acute to the near-degenerate obtuse triangular configuration is simulated by means of representative wave packet dynamics on two ab initio potential energy surfaces for the electronic ground (X2A′) and excited (42A′) states. Product state specifity is achieved by means of new iteration methods [W. Zhu, J. Botina and H. Rabitz, J. Chem. Phys. 108 (1998) 1953] which incorporate feedback from the control field. An additional restriction yields a smooth switch on and off behaviour of the optimized pulses. A windowed Fourier transform decomposes the optimized laser field into efficient pump–dump pulses