Signatures of conical intersections in two-dimensional electronic spectra

Femtosecond two-dimensional (2D) electronic spectroscopy is a versatile technique for the exploration of ultrafast photoinduced dynamics in complex molecular systems. We have performed the first computational simulation of a femtosecond 2D electronic spectrum for a model system with a conical intersection, using the wave-function version of the equation-of-motion phase-matching approach. It is shown that the 2D electronic spectrum of a two-state two-mode conical intersection simultaneously provides information on the complicated energy-level structure of the vibronically coupled states as well as on the time-dependent electronic population decay. The challenges and prospects of future simulations of 2D spectra of multi-mode conical intersections are briefly discussed. (paper)