Fully quantum simulation of surface enhanced Raman scattering from real-time ab-initio methods

Abstract

Surface enhanced Raman scattering (SERS) is the huge enhancement of the Raman signal of a mol. near a metal or nanoparticle surface due to coupling with the plasmon of the metal nanostructure. Although SERS was discovered several decades ago, a complete picture of the underlying mechanism still remains elusive due to the difficulty of treating the coupled metal-mol. system fully quantum mech.; the majority of previous studies have treated the plasmon classically accounting for only an electromagnetic enhancement of the Raman signal. However, it is well known that the SERS enhancement can be orders of magnitude larger than that predicted by electromagnetic enchancement. Here we go beyond the classical picture treating the plasmon and mol. fully quantum mech. through the use of real-time ab-initio methods. The presented work provides a deeper insight into the underlying mechanism of the SERS process.