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arXiv · 2511.06891

Plasmon resonance in a sub-THz graphene-based detector: theory and experiment

I. M. Moiseenko·E. Titova·M. Kashchenko·D. Svintsov
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Abstract

We present a combined experimental and theoretical study of photovoltage generation in a bilayer graphene (BLG) transistor structure exposed to subterahertz radiation. The device features a global bottom and split top gate, enabling independent control of the band gap and Fermi level, thereby enabling the formation of a tunable p-n junction in graphene. Measurements show that the photovoltage arises primarily through a thermoelectric mechanism driven by heating of the p-n junction in the middle of the channel. We also provide a theoretical justification for the excitation of two-dimensional plasmons at a record-low frequency of 0.13 THz, which manifests itself as characteristic oscillations in the measured photovoltage. These plasmonic resonances, activated by a decrease in charge carrier concentration due to opening of the band gap, lead to a local enhancement of the electromagnetic field and an increase in the carrier temperature in the junction region. The record-low frequency of plasmon resonance is enabled by the low carrier density achievable in the bilayer graphene upon electrical induction of the band gap.

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I. M. Moiseenko, E. Titova, M. Kashchenko, D. Svintsov. 2025-11-10. Plasmon resonance in a sub-THz graphene-based detector: theory and experiment. https://doi.org/10.1134/s1063739725601146

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