Flat Carbon Wonderland

Graphene, a single layer of carbon, is a condensed matter realization of the relativistic two-dimensional Dirac equation. After successful isolations of graphene in 2004, graphene has shown a cornucopia of interesting new physical phenomena with an exponentially increasing literature. The main driving forces behind the interests in graphene are two-fold: basic science and future technological applications. In this colloquium, I will review my recent works focusing on special interplay between electronic, magnetic, and geometric effect in graphene superstructures and their consequences.