Scattering-induced amplification of two-dimensional plasmons: electromagnetic modeling

Using two rigorous electromagnetic approaches, we study plasmon scattering in two-dimensional systems and show that plasmon amplification is possible in the presence of dc currents. Two scenarios are considered: plasmon scattering from an interface between different two-dimensional channels and plasmon reflection from electric contacts of arbitrary thickness. In each case, the effect of a dc current of the plasmon reflection and transmission coefficients and the plasmon power are both quantified. A resonant system is studied where plasmon roundtrip gain may exceed unity, showing the possibility of plasmon generation.