Assisted adiabatic population transfer

T. Rickes, L.P. Yatsenko, S. Steurwald, T. Halfmann, B.W. Shore, N.V. Vitanov, et al.. Efficient adiabatic population transfer by two-photon excitation assisted by a laser-induced Stark shift, J. Chem. Phys. 113 (2001) 534. 

The examples of CDF-aided vibrational energy transfer we have discussed modify the STIRAP process. Broadly put, the goal of an assisted adiabatic process is the complete transfer of population from an initial state to a selected target... 

Having suggested that the STIRAP process can be thought of as a special case of an assisted adiabatic process, we now examine another special case of an assisted adiabatic process, namely the composite STIRAP protocol proposed by Torosov and Vitanov [77]. This protocol uses a sequence of an odd number of pairs of delayed pulses (Figure 3.24) with carefully selected phases (listed in Table 3.4) to cancel by destructive interference the nonadiabatic transitions that reduce the efficiency of STIRAP-generated population transfer. We note that this protocol resembles the pulsed incoherent interference control protocol proposed by Shapiro et al. [78]. Torosov and Vitanov show that, for the triad of states illustrated in Figure 3.24, the efficiency of population transfer can be driven arbitrarily close to unity, for example, a deviation from unity of order 10 for the case of resonant excitation with three pairs of pulses. 

We have examined two assisted adiabatic transfer schemes designed to control the dynamical evolution of a quantum many-body system. That control is achieved by active manipulation with external fields that work cooperatively with coherence and interference effects embedded in the system quantum dynamics. The schemes we have discussed are a small subset of the many that have been proposed to induce complete transfer of population from an arbitrary initial state to a selected target state of a system, yet they illuminate the generic character of the... 

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