Tunable Screening of Inter-Contact Plasmons by a Recessed Gate in Field-Effect Transistor with Two-Dimensional Electron Channel

This work studies field-effect transistors (FET) with two-dimensional electron channel. It is theoretically shown that the frequencies of higher-order resonances of the ungated plasmon modes can be effectively tuned by the gate-voltage variation at a short recessed gate, which mimic conventional gated plasmon resonance but with a much stronger efficiency. The calculated THz absorption spectra of a FET with a short recessed gate are presented. Results show that the frequency of the second-order inter-contact plasmon resonance can be tuned by applying the gate voltage producing the electron density variation in the short gated region of the channel.