Control incoherent

If the dephasing time of the coherent phonons depend critically on the carrier density, photo-injection of carriers with the second pump pulse can annihilate them partially or completely, depending on its fluence but not on its relative timing. Such incoherent control was demonstrated for the LO phonons of GaAs [37],... 

Serious mental disorders fundamentally alter one s personality. Evidence from controlled studies demonstrates that antipsychotics can normalize thought processes. Some claim that the involuntary administration of these drugs violates a patient s freedom of speech. In fact, with the onset of a psychotic episode, patients normal mental processes become loose, rambling, illogical, circumstantial, incoherent, and inappropriately concrete and are often characterized by bizarre thought and speech patterns. Delusional ideas may dominate, with or without visual or auditory hallucinations. 

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. 

M. Shapiro, Z. Chen, and P. Brumer. Simultaneous control of selectivity and yield of molecular dissociation pulsed incoherent interference control. Chem. Phys., 217(2) 325—340(1997). 

FROM COHERENT TO INCOHERENT DYNAMICAL CONTROL OF OPEN QUANTUM... 

The relaxation rate R t) described by Eqs. (4.49)-(4.51) embodies our universal recipe for dynamically controlled relaxation [10, 21], which has the following merits (i) it holds for any bath and any type of interventions, that is, coherent modulations and incoherent interruptions/measurements alike (ii) it shows that in order to suppress relaxation, we need to minimize the spectral overlap of G( ), given to us by nature, and Ffo)), which we may design to some extent (iii) most importantly, it shows that in the short-time domain, only broad (coarse-grained) spectral features of G( ) and Ffa>) are important. The latter implies that, in contrast to the claim that correlations of the system with each individual bath mode must be accounted for, if we are to preserve coherence in the system, we actually only need to characterize and suppress (by means of Ffco)) the broad spectral features of G( ), the bath response function. The universality of Eqs. (4.49)-(4.51) will be elucidated in what follows, by focusing on several limits. 

FROM COHERENT TO INCOHERENT DYNAMICAL CONTROL OF OPEN QUANTUM SYSTEMS 165 4.4.3.1 Dynamically Modified Decay Rates... 

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