Dispersion properties of plasma excitations in tunnel-coupled bilayer electron systems

Plasma excitations in a bilayer electron system with weak tunnel coupling have been considered. The effect of the spatial symmetry of the system on the spectrum of plasma excitations has been analyzed. It has been shown experimentally and theoretically that, despite the fundamentally different origins of plasma excitations in systems with different spatial symmetries, their physical properties in the energy range above the tunneling parameter are similar.