Phonon drag in two-dimensional electron systems

Abstract

Abstract The phonon drag of 2D electrons has been studied on the interfaces in bicrystals and on the cleavage (111) surfaces of Germanium; on the inversion layer on (111), (100) and vicinal to (100) planes of Silicon. In all these cases the phonon drag was about two orders of magnitude larger than in metals with the same charge density. This is due to the drag of surface electrons by nonequilibrium phonon of the whole specimen. The magnitude of the phonon drag depends on the value of qle, q is the phonon wave vector and le is the electron mean free path. The Kohn resonance of phonons with Fermi surface and Lifshitz topological transition on Fermi surface of 2D electrons produce sharp singularities in the phonon drag dependence of the surface charge density.