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Bandurin, D., Svintsov, D., Gayduchenko, I., Xu, S., Principi, A., Moskotin, M., et al. (2019). Resonant terahertz photoresponse and superlattice plasmons in graphene field-effect transistors. In APS March Meeting (F14.015).
Abstract: Plasmons, collective oscillations of electron systems, can couple light and electric current, and thus can be used to create compact photodetectors, radiation mixers, and spectrometers. Despite the effort, it has proven challenging to implement plasmonic devices operating at THz frequencies. The material capable to meet this challenge is graphene as it supports long-lived electrically-tunable plasmons. In this talk, we will demonstrate plasmon-assisted resonant detection of THz radiation by antenna-coupled graphene FETs that act as both rectifying elements and plasmonic Fabry-Perot cavities amplifying the photoresponse. We will show that by varying the plasmon velocity using gate voltage, our detectors can be tuned between multiple resonant modes, a functionality that we apply to measure plasmons' wavelength and lifetime in graphene as well as to probe collective modes in its moire minibands. Our approach offers a convenient tool for further plasmonic research that is often difficult under non-ambient conditions and promises a viable route for various THz applications. We acknowledge Leverhulme Trust, Russian Science Foundation Grants N18-72-00234 and 17-72-30036, Russian Foundation for Basic Research No. 18-57-06001 and 16-29-03402.
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Matyushkin, Y., Fedorov, G., Moskotin, M., Danilov, S., Ganichev, S., & Goltsman, G. (2020). Gate-mediated helicity sensitive detectors of terahertz radiation with graphene-based field effect transistors. In Graphene and 2dm Virt. Conf..
Abstract: Closing of the so-called terahertz gap results in an increased demand for optoelectronic devices operating in the frequency range from 0.1 to 10 THz. Active plasmonic in field effect devices based on high-mobility two-dimensional electron gas (2DEG) opens up opportunities for creation of on-chip spectrum [1] and polarization [2] analysers. Here we show that single layer graphene (SLG) grown using CVD method can be used for an all-electric helicity sensitive polarization broad analyser of THz radiation. Allourresults show plasmonic nature of response. Devices are made in a configuration ofa field-effect transistor (FET) with a graphene channel that has a length of 2 mkm and a width of 5.5 mkm. Response of opposite polarity to clockwise and anticlockwise polarized radiation is due to special antenna design (see Fig.1c) as follow works [2,3]. Our approaches can be extrapolated to other 2D materials and used as a tool to characterize plasmonic excitations in them. [1]Bandurin, D. A., etal.,Nature Communications, 9(1),(2018),1-8.[2]Drexler, C.,etal.,Journal of Applied Physics, 111(12),(2012),124504.[3]Gorbenko, I. V.,et al.,physica status solidi (RRL)–Rapid Research Letters, 13(3),(2019),1800464.
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