Resonant Plasmonic Terahertz Detection in Gated Graphene p-i-n Field-Effect Structures Enabled by Nonlinearity from Zener-Klein Tunneling

We propose and analyze the terahertz (THz) detectors based on a gated\ngraphene p-i-n (GPIN) field-effect transistor (FET) structure. The\nreverse-biased i-region between the gates plays the role of the electrons and\nholes injectors exhibiting nonlinear $I-V$ characteristics due to the\nZener-Klein tunneling. This region enables the THz signal rectification, which\nprovides their detection. The gated regions serve as the electron and hole\nreservoirs and the THz resonant plasma cavities. The resonant excitation of the\nelectron and hole plasmonic oscillations results in a substantial increase in\nthe THz detector responsivity at the signal frequency close to the plasma\nfrequency and its harmonics. Due to the specifics of the i-region AC\nconductance frequency dependence, associated with the transit-time effects, the\nGPIN-FET response at the frequency, corresponding to the excitation of a higher\nplasmonic mode, can be stronger than for the fundamental mode. The GPIN-FETs\ncan exhibit fairly high responsivity at room temperatures. Lowering of the\nlatter can result in its further enhancement due to weakening of the carrier\nmomentum relaxation.\n