Transit‐Time Instability Mechanism in Lateral Graphene n+‐i‐n‐i‐n+ Structure with Transverse Terahertz Pasmonic Resonant Cavity

Abstract

The terahertz (THz) plasmonic instability in the lateral graphene structure (LGS) with the n+‐i‐n‐i‐n+ junction in its graphene channel (GC) is analyzed. The i‐regions in the LGS n+‐i‐n‐i‐n+ GC plays the role of the transit spaces of the electrons emitted from the n+‐regions (the emitters) and collected by the gated n‐region (collector) and the side contact to the latter. The interband Zener–Klein tunneling (ZKT) in the i‐regions also contributes to the currents received by the n‐region. Simultaneously, the n‐region constitutes the transverse resonant plasmonic cavity, in which the plasmons with the wave vector directed perpendicular to the electron propagation direction are excited. The plasmonic instability in the LGSs is associated with the transit‐time negative dynamic conductance of the i‐regions supported by the plasmonic resonances in the n‐region. The self‐excitation of plasmonic oscillations associated with the instability in the LGS with sub‐micrometer i‐regions and supplied with a proper antenna can lead to the emission of THz radiation. The LGS can form periodic arrays, which can serve as an active distributed antenna.