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