Redfield, multilevel theory

Jean J M, Fleming G and Friesner R 1992 Application of a multilevel redfield theory to electron transfer in condensed... 

A more general approach is required to interpret the current experiments, Jean and co-workers have developed multilevel Redfield theory into a versatile tool for describing ultrafast spectroscopic experiments [22-25], In this approach, terms neglected at the Bloch level play an important role for example, coherence transfer terms that transform a coherence between levels i and j into a coherence between levels j and k ( /t - = 2) or between levels k and l ( f - j - 2, k-j = 2) and couplings between populations and coherences. Coherence transfer processes can often compete effectively with vibrational relaxation and dephasing processes, as shown in Fig. 4 for a single harmonic well, initially prepared in a superposition of levels 6 and 7. The lower panel shows the population of levels 6 and 7 as a function of time, whereas the upper panels display off-diagonal density matrix ele-... 

Figure 6. Population decay of the initial state in a barrierless double-well system calculated using multilevel Redfield theory [25]. The vibrational frequency is 60 cm1. (----------)...

To apply Redfield theory to these real-world condensed-phase problems, it will clearly be essential to construct appropriate reduced models from classical simulations, as in the dispersed polaron method of Warshel [67,68]. Carrying this process out for a general multilevel, as opposed to a two-level, system will necessitate considerable study as to the most... 

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