Title: Optical Spectroscopy and Twistronics: Engineering Novel States in Atomically Thin Materials

Abstract

Two-dimensional (2D) materials, such as graphene and monolayers of transition metal dichalcogenides (TMDs), exhibit exceptional light-matter interactions due to their reduced dimensionality and unique crystal symmetries. While only a few dozen layered compounds have been experimentally synthesized, theoretical predictions suggest that over 5,000 stable 2D materials await discovery, with properties ranging from semiconducting to magnetic and topological. These materials can be stacked to form van der Waals heterostructures or twisted to create moiré patterns, enabling unprecedented control over their electronic and optical properties. The ability to manipulate these properties has led to the emerging field of twistronics, which has become a focal point in the study of van der Waals materials.

In this seminar, I will discuss insights from my recent studies on linear and nonlinear optical spectroscopy of atomically thin semiconductors and twisted heterostructures, emphasizing their potential applications in optoelectronics and nanophotonics. Special attention will be given to the investigation of novel quantum states whose energies are tunable via external electric/magnetic fields and interlayer twist. I will also highlight approaches for confining and transporting excitonic states, paving the way for their use in information processing technologies, such as excitonic circuits. Finally, I will outline future research directions, including opportunities for advancing quantum optics, nanophotonics, and hybrid magnetic structures in this multidisciplinary field.