Prospects for the application of two-dimensional materials to terahertz-band communications

In this paper, we review some of the key properties of emergent two-dimensional (2D) materials that make them potentially attractive for application in the hardware components needed to enable future communications in the terahertz (THz) band. Graphene is a material that has attracted enormous interest in recent years, due to its high electrical and thermal conductivities, and its capacity to exhibit pronounced and controlled plasmonic effects. Here we describe several schemes that seek to exploit these characteristics for the sourcing, manipulating, and detection of THz signals. Another class of 2D materials that are also promising for use in this area are the transition metal dichalcogenides (TMDs). These include materials such as MoS2 and WS2, which, like graphene, exhibit a multi-valley conduction band structure. In contrast to graphene, however, the valleys of TMDs are highly asymmetric, a characteristic that may allow the realization of novel high-frequency sources capable of THz operation.