ABSTRACT
The possibility of graphene’s existence or that of a twodimensional (2D) allotrope of carbon has been theoretically studied for 60 years. Often, the term graphene was used to describe the properties of carbon allotropes [1-3]. However, after four decades it has been realized that graphene also provides an excellent condensed matter analogue of (2 + 1)-dimensional quantum electrodynamics [4-7], thereby exposing graphene to a thriving theoretical “toy” model [7]. Graphene was expected to be unstable due to the formation of curved structures such as soot, fullerenes, and nanotubes. Further, graphene was believed not to exist in its free state. Unexpectedly, in 2004, the prediction of graphene’s existence became true when freestanding graphene was discovered by Geim and Novoselov [8,9]. Moreover, the follow-up experiments demonstrated that its charge carriers were indeed massless Dirac fermions [10,11]. As a result of this phenomenon, graphene is indeed the material of choice for numerous
researchers. Geim and Novoselov shared the 2010 Nobel Prize in Physics for the discovery of graphene [12-14].
