Casimir Effects in 2D Dirac Materials (Scientific Summary)

Abstract

Fluctuation induced interactions originating from electromagnetic fields give rise to the Casimir force. Even though this is a universal interaction, because of the interplay between the response properties of interacting objects and their geometry the Casimir force can have many types of scaling laws, variations in magnitude and sign, and wide dependences on characteristic constants. The Casimir interaction is especially prominent in systems with reduced dimensions at micron and submicron scale separations. In recent years, examining this type of force for many nanostructured and chemically inert materials has become of great interest. Here, we review advances in the field of Casimir physics in the context of 2D layered materials with Dirac energy spectrum, such as graphene and related materials. The focus is on Casimir interactions and frictional effects with emphasis on the zero-point energy summation approach used for calculations. After giving an overview of this powerful technique, the optical response properties of graphene described with different models is presented. Numerical and analytical results in terms of characteristic behaviors for Casimir and Casimir-Polder interactions involving a stack of parallel layers are summarized. Other key results in the expanded graphene materials as well as their Casimir friction are also presented.