📝 SummarXiv

Abstract

We study surface plasmons in minimally-twisted bilayer graphene that contains a triangular network of partial dislocations (or AB-BA domain walls) hosting one-dimensional electronic states. We calculate plasmon dispersion by solving classical equations of motion for charge dynamics on the network links with impedance boundary conditions at the network nodes. The plasmon band structure is shown to be quasi-periodic in frequency and damped everywhere except at high-symmetry points of the moir\'e Brillouin zone. We compare our network-based formalism with the conventional random phase approximation and discuss when each approach is valid. Calculations of plasmon waves launched by local scatterers are presented to simulate terahertz nano-imaging experiments.