Resonant plasmonic terahertz detection in gated graphene p-i-n field-effect structures enabled by the Zener-Klein tunneling nonlinearity

TL;DR

This paper proposes a novel graphene-based THz detector utilizing Zener-Klein tunneling in a gated p-i-n structure, achieving high responsivity through resonant plasmonic excitations at room temperature.

Contribution

It introduces a new graphene p-i-n FET design that leverages nonlinear tunneling and plasmonic resonances for efficient THz detection, with potential for enhanced room-temperature performance.

Findings

Resonant excitation of plasmonic oscillations increases detector responsivity.

Higher plasmonic modes can produce stronger responses than fundamental modes.

Responsivity can be further improved by reducing carrier momentum relaxation.

Abstract

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