Haruka maeda 

University of Virginia 
Adiabatic Rapid Passage and Nonlinear PhaseLocking in Atomic Population Control
Wednesday, October 11, 2006
4:30 p.m.
CW 102
When applying to a Rydberg atom a weak microwave (MW) field whose frequency nearly matches the classical Kepler frequency of the electron, an electronprobability distribution is localized in space and periodically oscillates synchronized with the MWfield phase for a long time: An “eternal” nondispersing wave packet is created, which resembles a onedimensional classical atom, as the wave packet localized nearly along the polarization axis of MW field does not manifest dispersion as time evolves. By exploiting the synchronization of the electron motion in the atom, which can be thought of as a nonlinear phaselocking of electron's radial motion based on the corresponding classical dynamics, we have demonstrated that binding energy of Rydberg atoms can be manipulated by adiabatically increasing or decreasing the MW frequency. In quantum mechanics, this process can be viewed as a ladderclimbing, i.e., population transfer of Rydberg atoms through a sequence of singlephoton adiabatic rapid passages (ARPs). We have also found that the same population transfer in the Rydberg ladder can be achieved through a single multiphoton ARP instead of driving transitions via a series of onephoton ARPs. Again, we show that the nonlinear phaselocking is responsible for the classical dynamics of the population transfer through the multiphoton ARP.