Stimulated Raman adiabatic passage with temporal pulselets

Stimulated Raman adiabatic passage (STIRAP) is a well established technique whereby two pulses, SS preceding PP, induce complete population transfer between states 1 and 3 of a three-state chain, 1–2–3. Traditionally, the SS and PP pulse envelopes are taken as positive (often with Gaussian form of time dependence). However, when the envelope undergoes a sign change during the pulse, as occurs with pulses in which an abrupt phase change of ππ occurs and whose temporal area (time-integrated Rabi frequency) is zero, then the simple population transfer need not occur. Instead there may occur multiple adiabatic passages, in which the population may ultimately be left in either state 1 (a double STIRAP) or state 3 (a triple STIRAP) or, with suitable pulse delay, in a superposition of these two states. These adiabatic changes offer possibilities to produce final-state probability amplitudes with either positive or negative signs. We here show simulated examples of such behavior, and discuss the adiabatic conditions needed for such excitation to occur.