Spectrum of plasma excitations in a plasmonic crystal fabricated in an AlGaAs/GaAs heterostructure

We report on the experimental study of the spectrum of plasma excitations in a plasmonic crystal fabricated from the two-dimensional electron system in an AlGaAs/GaAs semiconductor heterostructure. We perform a comprehensive research on the mode frequency and relaxation as a function of the gate width across different plasmonic crystal periods. Importantly, we develop an analytical approach that accurately describes the behavior of plasma excitations in plasmonic crystals, providing insights into the fundamental physics of plasmonic systems.