Controllability on relaxation-free subspaces: On the relationship between adiabatic population transfer and optimal control

Understand

We consider the optimal control problem of transferring population between states of a quantum system where the coupling proceeds only via intermediate states that are subject to decay.

• We pose the question whether it is generally possible to carry out this transfer.
• For a single intermediate decaying state, we recover the Stimulated Raman Adiabatic Passage (STIRAP) process which we identify as the global optimum in the limit of infinite control time.
• We also present analytic solutions for the case of transfer that has to proceed via two consecutive intermediate decaying states.