Speaker: Dr. Hebin Li, Florida International University
Abstract: Many-body interactions and correlations are fundamental in understanding collective and emergent phenomena that cannot be understood by a simple extrapolation of the microscopic laws of a few particles. An experimentally confirmed understanding of many-body quantum dynamics is essential for many problems in cold atoms/molecules, optical atomic clocks, semiconductors, and photosynthesis.
In this presentation, I will introduce the idea of optical two-dimensional coherent spectroscopy (2DCS) and its experimental implementations in our lab. I will then talk about its applications in studying many-body interactions and dynamics in atoms and semiconducting 2D materials. In atomic systems, double-quantum 2DCS provides an extremely sensitive and background-free detection of dipole-dipole interactions. The technique can also be extended to multi-quantum coherent spectroscopy to probe multiple-atom correlated states (Dicke states). Optical 2DCS is also a powerful tool for studying carrier dynamics and coupling in semiconductors including 2D semiconductors. Optical 2DCS can probe valley coherence and measure the homogeneous linewidth in the presence of inhomogeneous broadening. More recently, the technique was used to probe polaron dynamics in a doped MoSe2 monolayer.