Coherent Multidimensional Spectroscopies: Advanced Spectroscopic Techniques to Unveil Complex Dynamics

Femtosecond coherence spectroscopy is a family of ultrafast techniques that utilize ultrafast laser pulses to prepare and monitor coherent states in resonant or non-resonant samples. Among coherence spectroscopies, 2D electronic spec- troscopy (2DES) techniques have recently gained particular interest given their capability of following ultrafast processes in real-time. Indeed, 2DES is widely exploited to unveil subtle details of ultrafast relaxation dynamics, including energy and charge transport, in complex media such as biological and artificial light-harvesting complexes and solid-state materials. Particularly meaningful is the possibility of assessing coherent mechanisms active in the transport of excitation energy in these materials. In this chapter, the main technical aspects of 2DES will be reviewed by illustrating specific relevant applications to different systems. Current challenges and still debated perspectives will be presented