Resonant terahertz detection using graphene plasmons

Abstract

Plasmons, collective oscillations of electron systems, can efficiently couple light and electric current, and thus can be used to create sub-wavelength photodetectors, radiation mixers, and on-chip spectrometers. Despite considerable effort, it has proven challenging to implement plasmonic devices operating at terahertz frequencies. The material capable to meet this challenge is graphene as it supports long-lived electrically tunable plasmons. Here we demonstrate plasmon-assisted resonant detection of terahertz radiation by antenna-coupled graphene transistors that act as both plasmonic Fabry-Perot cavities and rectifying elements. By varying the plasmon velocity using gate voltage, we tune our detectors between multiple resonant modes and exploit this functionality to measure plasmon wavelength and lifetime in bilayer graphene as well as to probe collective modes in its moiré minibands. Our devices offer a convenient tool for further plasmonic research that is often exceedingly difficult under non-ambient conditions (e.g. cryogenic temperatures) and promise a viable route for various photonic applications.

Flexible Photodetector Based on 2D Materials: Processing, Architectures, and Applications

“…Graphene is known for its high carrier mobility, optical transparency and 0 eV bandgap that enables light absorption in a wide energy spectrum (VIS to THz) . However, it has a light absorptivity of only 2.3%, consequently leading to low photoresponses.…”

Ultra-long wavelength Dirac plasmons in graphene capacitors

“…Our experiment paves the way to active plasma resonance transistors working in the 0.1 1 THz  domain, above the natural cutoff ∼0.1 THz of conventional graphene field-effect transistors [21,22]. Building on this first demonstration performed at cryogenic temperatures, a room temperature variant can be envisioned by scaling down the sample size and the plasmon wave length by a factor 10 to accommodate the phononlimited mean free path of 0.7 μm at 300 K. During the reviewing process, we became aware of a related work [23] demonstrating the resonant detection of THz radiation using graphene plasmons. These achievements might in particular lead to the conception of novel detectors in the 600 GHz frequency domain, highly desirable for air-craft RADARs operating in the mm-range, with a resolution ultimately limited by hot electron effects [14,24,25].…”

Plasmonic Helicity‐Driven Detector of Terahertz Radiation

“…The TeraFET applications already being commercialized include sub‐THz and THz detectors implemented in Si, GaAs, GaN, graphene (see ref. and references therein), and other materials systems (for a review see ref. ).…”

“…In existing TeraFET applications (mainly using the “non‐resonant” regime of operation), this obstacle is partially overcome due to tunability of the intrinsic device response by the gate voltage. Very recently, there appeared an opportunity for a further revolutionary breakthrough in this direction which is based on experimental results obtained this year by different groups: A resonant tunable response with clearly distinguishable contributions of several plasmonic harmonics was obtained in a graphene TeraFET A possibility to integrate broadband THz antennas with a TeraFET was experimentally demonstrated .…”

“…The latter has a sharp resonant frequency dependence and, therefore, can be easily distinguished from the smooth antennas‐induced contribution even for small U a and U b . Such a resonant dependence has been already observed in the clean graphene‐based TeraFETs …”