Abstract-Resonant Terahertz Detection Using Graphene Plasmons

D. A. Bandurin, D. Svintsov, I. Gayduchenko, S. G. Xu, A. Principi, M. Moskotin, I. Tretyakov, D. Yagodkin, S. Zhukov, T. Taniguchi, K. Watanabe, I. V. Grigorieva, M. Polini, G. Goltsman, A. K. Geim, G. Fedorov

https://arxiv.org/abs/1807.04703

Plasmons, collective high-frequency oscillations of electron systems, can in theory be used to create compact solid-state devices for on-chip spectroscopy of terahertz (THz) radiation. Despite significant interest and experimental efforts, it has proven challenging to implement such devices. The material that can be used to meet this challenge is graphene as it supports long-lived electrically-tunable plasmons. Here, we demonstrate plasmon-assisted detection of THz radiation by antenna-coupled graphene field effect transistors that act as both rectifying elements and plasmonic Fabry-Perot cavities amplifying the photoresponse. By varying the plasmon velocity with gate voltage, we tune our detectors between different resonant modes and exploit this functionality to measure plasmon wavelength and lifetime. Our work opens a convenient venue for further plasmonic research that is often exceedingly difficult under non-ambient conditions (e.g., at cryogenic temperatures and high magnetic fields). The demonstrated resonant detection also promises a viable route for various THz applications.

Abstract-Dual origin of room temperature sub-terahertz photoresponse in graphene field effect transistors

D. A. Bandurin,  I. Gayduchenko, Y. Cao,  M. Moskotin, A. Principi,  I. V. Grigorieva, G. Goltsman, G. Fedorov, D. Svintsov,

https://aip.scitation.org/doi/abs/10.1063/1.5018151

Graphene is considered as a promising platform for detectors of high-frequency radiation up to the terahertz (THz) range due to its superior electron mobility. Previously, it has been shown that graphene field effect transistors (FETs) exhibit room temperature broadband photoresponse to incoming THz radiation, thanks to the thermoelectric and/or plasma wave rectification. Both effects exhibit similar functional dependences on the gate voltage, and therefore, it was difficult to disentangle these contributions in previous studies. In this letter, we report on combined experimental and theoretical studies of sub-THz response in graphene field-effect transistors analyzed at different temperatures. This temperature-dependent study allowed us to reveal the role of the photo-thermoelectric effect, p-n junction rectification, and plasmonic rectification in the sub-THz photoresponse of graphene FETs.