Multi-THz Pump Bandwidth Activation of Ultrafast Anharmonic Vibrational Coupling

We use first-principles calculations to model multi-THz excitation and ultrafast coherent energy flow between vibrational degrees of freedom in gas-phase fluorobenzene. To accomplish this, we compute anharmonic coupling constants and use coupled equations of motion to model the ultrafast dynamics. We determined the role of anharmonic coupling as well as the symmetry of the vibrational modes in intramolecular energy transfer. The results from this modeling are guiding measurements of anharmonic coupling in fluorobenzene with a new multi-THz pump, femtosecond stimulated Raman scattering (FSRS) probe experimental setup.