Diana Qiu1
Yale University1
In low-dimensional and nanostructured materials, the optical response is dominated by correlated electron-hole pairs---or excitons---bound together by the Coulomb interaction. Understanding the energetics and dynamics of these excitons is essential for diverse applications across optoelectronics, quantum information and sensing, as well as energy harvesting and conversion. By now, it is well-established that these large excitonic effects in low dimensional materials are a combined consequence of quantum confinement and inhomogeneous screening. However, many challenges remain in understanding their dynamical processes, especially when it comes to correlating complex experimental signatures with underlying physical phenomena through the use of quantitatively predictive theories. In this talk, I will discuss how excitons in low-dimensional and nanostructured materials, such as monolayer transition metal dichalcogenides and layered perovskites, differ from typical bulk materials. In particular, we will look at how long-range quantum interactions can give rise ultrafast energy transport in low dimensions and explore the transfer of spin, charge and chirality across heterointerfaces. Finally, we will explore the kinetics of phase transitions that accompany Li intercalation in layered van der Waals materials, which has promising energy storage applications and can drive the formation of new charge density wave (CDW) phases.