Characterization of PbSe Quantum Dot Excitons Using Ultrafast Multiresonant Coherent Multidimensional Spectroscopy

Book excerpt: Coherent multidimensional spectroscopy (CMDS) is a family of techniques that uses multiple laser pulses to create and monitor multiple quantum states for insight on structure and dynamics. This dissertation details the application multi-resonant CMDS to the excitonic transitions of PbSe quantum dots. We perform numerical simulations of CMDS on a model excitonic system to understand the spectral and temporal signatures of state-filling, with specific regard to correlated inhomogeneity. Experiments use 50 femtosecond pulses to resolve the excited state dynamics and structure of the near bandgap excitons. We use solvent as an internal standard to determine the absolute third-order non-linear susceptibility of quantum dots. We combine transient grating and transient absorption measurements to provide a fully-phased spectrum of the non-linear susceptibility. Finally, we overview preliminary results of novel experiments and consider their possible role in future experiments. This work provides foundational principles for the application of MR-CMDS spectroscopy of semiconductor excitons.