Raman spectroscopy of molecular junctions is a promising diagnostic and control tool. We present a model for charge-transfer contribution to surface-enhanced Raman spectroscopy, generalizing previous considerations to strong laser pulses of arbitrary time dependence. The approach paves a way to realistic simulations of Raman spectroscopy experiments in molecular junctions. We demonstrate that the optical response of molecular conduction junctions is correlated with the electron transport. Feynman diagrams responsible for such similarity are analyzed, and a possible explanation for observed (anti)correlated behavior of Stokes signal and conductance is proposed.

• Received 5 January 2011

DOI:https://doi.org/10.1103/PhysRevB.84.075447