The paper examines the effect of irreversible dissipation from the intermediate state on the efficiency of population transfer by partially overlapping delayed pulses in three-state systems. Several general approximations to the final-state population for both the intuitive and counterintuitive pulse sequences are derived. They show that the loss of transfer efficiency is much stronger for the intuitive pulse sequence, as then the intermediate state is significantly populated during the transfer. For the counterintuitive sequence, the damping of the final-state population is found to be exponential for small decay rates and polynomial for large ones; moreover, the range of decay rates, over which the transfer efficiency remains high, is proportional to the squared pulse area. The paper also presents an analytically solvable model, involving smooth delayed pulses, as well as numerical results and analytic approximations for Gaussian pulses.

• Received 31 March 1997

DOI:https://doi.org/10.1103/PhysRevA.56.1463