Fast population transfer engineering of three-level systems
  We design, by invariant-based inverse engineering, resonant laser pulses to perform fast population transfers in three-level systems. The efficiency and laser intensities are examined for different protocols. The energy cost to improve the fidelity is quantified. The laser intensities can be reduced by populating the intermediate state and by multi-mode driving. 
Xi Chen and J. G. Muga
quant-ph