We present a method for achieving complete population transfer in a two-state quantum system via adiabatic time evolution in which, contrary to conventional rapid adiabatic passage produced by chirped pulses, there occurs no crossing of diabatic energy curves: there is no sign change of the detuning. Instead, we use structured pulses, in which, in addition to satisfying conditions for adiabatic evolution, there occurs a sign change of the Rabi frequency when the detuning is zero. We present simulations that offer simple geometrical interpretation of the two-dimensional motion of the Bloch vector for this system, illustrating how both complete population inversion and complete population return occur for different choices of structured pulses.
@article{arxiv.0910.4143,
title = {Rapid adiabatic passage without level crossing},
author = {A. A. Rangelov and N. V. Vitanov and B. W. Shore},
journal= {arXiv preprint arXiv:0910.4143},
year = {2010}
}