Non-Trivial Excited State Coherence Due to Two Uncorrelated Partially   Coherent Fields
  We analyze a model where a closed $V$ system is excited by two uncorrelated partially coherent fields. We use a collisionally broadened CW laser, which is a good model for an experimentally realizable partially coherent field, and show that it is possible to generate excited state coherences even if the two fields are uncorrelated. This transient coherence can be increased if splitting between the excited states is reduced relative to the radiation coherence time, $\tau_{d}$. For small excited state splitting, one can use this scheme to generate a long lived coherent response in the system. 
Z.S. Sadeq
quant-ph