SEMINAR 2025

Abstract

The absorption of light by matter follows a universal mechanism that drives crucial reactions in both natural and engineered systems. Processes ranging from photosynthesis, to photocatalysis, to energy harvesting in photovoltaic cells all begin in the same way: the absorption of light creates an exciton—a correlated electron-hole pair that carries energy rather than charge. Exciton dynamics determine the effectiveness of photovoltaic energy harvesting and photosynthesis, while excitonic manipulation enables the optical preparation and transduction of quantum states and the potential to integrate the fast speed of photons into electronics. However, the quantitative prediction of these exciton dynamics is a complicated problem that requires accurate quantum mechanical descriptions of many-electron interactions. In this talk, I will discuss three different frontiers related to the first principles understanding of exciton dynamics and nonlinear optics in two-dimensional materials: the observation of massless excitons and their consequences for energy transport, exciton effects in nonlinear optics in the nonperturbative regime, and machine learning based acceleration of first principles calculations of these effects.