Adiabatic Passage Control Methods for Ultracold Alkali Atoms and Molecules via Chirped Laser Pulses and Optical Frequency Combs

The adiabatic passage-based control methods have been developed to advance a cutting-edge research area of ultracold physics. We studied the controlled excitation of Rydberg atoms, population inversion within hyperfine states of alkali atoms, and the control of internal degrees of freedom in diatomic polar molecules. We have developed an optical frequency comb-based method for creation of ultracold molecules. These works are in demand due to an urgent need in the novel methods for the production of ultracold molecules and for ultracold quantum control. We make use of chirped pulses and optical frequency combs with modulation in the form of the sinusoidal function. This allowed us to achieve the adiabatic regime of excitations, which is a robust approach for experimental realization. The novelty of the implementation of optical frequency combs for the formation of ultracold molecules relies on the creation of a quasi-dark state leading to insignificant population of the transitional, vibrational state manifold and, thus, to efficient mitigation of decoherence in the system. Moreover, the parity of the chirp of the incident electromagnetic field was shown to be an important factor in achieving a predetermined quantum yield.