Surface acoustic plasmons at a p-n junction
Blank A. Ya. , Gulyaev Yu. V.
A quasilongitudinal surface wave can propagate along the interface between two conducting media in which the current carriers have very different effective masses. In contrast with the familiar collective branch in the spectrum of a two-component plasma—the acoustic plasmon— this new branch has an unusual dispersion, which is proportional to the square root of the wave vector. This wave can be observed at a p-n junction or at a metal-semiconductor junction.