Manipulation of Rydberg atoms by terahertz pulses

In this paper, ultrashort, unipolar electric-field (terahertz) pulses have been used to coherently control population transfer between Rydberg states in lithium atom. Our numerical results show that populations of lithium atoms can be driven to lower or higher n levels with a train of half-cycle pulses, and the the transition rate is sensitive to the static-electric-field strength, the main laser frequency, the optical pulse profile, and the chirp of the laser pulse. If the paramerters of the half-cycle pulses is optimized appropriately, the population can be transferred to the target state completely.