title: Novel relativistic plasma excitations in a gated two-dimensional electron system.
abstract: The microwave response of a two-dimensional electron system (2DES) covered by a conducting top gate is investigated in the relativistic regime for which the 2D conductivity σ_{2D}>c/2π. Weakly damped plasma waves are excited in the gated region of the 2DES. The frequency and amplitude of the resulting plasma excitations show a very unusual dependence on the magnetic field, conductivity, gate geometry, and separation from the 2DES. We show that such relativistic plasmons survive for temperatures up to 300 K, allowing for new room-temperature microwave and terahertz applications.
authors: Institute of Solid State Physics, RAS, Chernogolovka 142432, Russia.
authors: V M
authors: VM
authors: Muravev
authors: Institute of Solid State Physics, RAS, Chernogolovka 142432, Russia.
authors: P A
authors: PA
authors: Gusikhin
authors: Institute of Solid State Physics, RAS, Chernogolovka 142432, Russia.
authors: I V
authors: IV
authors: Andreev
authors: Institute of Solid State Physics, RAS, Chernogolovka 142432, Russia.
authors: I V
authors: IV
authors: Kukushkin