Effect of contacts on terahertz plasma resonances in two-dimensional electron systems

We study the effect of side contacts on plasma oscillations in two-dimensional (2D) electron systems by numerical simulation. Our model is based on the kinetic electron transport equation and the self-consistent Poisson equation. We find that the contacts absorb the energy of plasma oscillations excited in the 2D electron channel and consequently this effect can be a dominant damping mechanism, surpassing the damping due to the electron collisions. We estimate the damping rate caused by the contacts and discuss its dependence on the real contact injection properties and temperature.