Coherent quantum control of internal conversion: S-2 <-> S-1 in pyrazine via S-0 <-> S-2/S-1 weak field excitation

摘要

Coherent control of internal conversion (IC) between the first (S-1) and second (S-2) singlet excited electronic states in pyrazine, where the S-2 state is populated from the ground singlet electronic state S-0 by weak field excitation, is examined. Control is implemented by shaping the laser which excites S-2. Excitation and IC are considered simultaneously, using the recently introduced resonance-based control approach. Highly successful control is achieved by optimizing both the amplitude and phase profiles of the laser spectrum. The dependence of control on the properties of resonances in S-2 is demonstrated.