Supported by the National Natural Science Foundation of China under Grant No. 61078065, Natural Science Foundation of Ningbo City under Grant No. 2008A61009, and K.C. Wong Magna Foundation in Ningbo University
In this paper, we investigate a two electronic level system with vibrational modes coupled to a Brownian oscillator bath. The difference frequency generation (DFG) signals and sum frequency generation (SFG) signal...