Our group conducts research in condensed-matter theory. We study semiconductors, nanostructures, graphene, and other two-dimensional crystals. We are interested in electronic, excitonic, mechanic, and plasmonic properties of such materials. Our recent research highlights is a series of works on plasmons and polaritons in graphene and other 2D van der Waals crystals. We collaborate with a number of experimentalists, both at UCSD and at large.