Sound modes of a two-dimensional electron gas bound to a helium film

Observation of the Polaronic Transition in a Two-Dimensional Electron System

“…[4][5][6][7] This is due to the existence of an additional controllable parameter, the film thickness d. This parameter determines the strength of the image potential, the ripplon dispersion relation, the nature of the electron-electron interactions, and the strength of the electron-ripplon coupling. In particular, one expects the formation of a surface polaron when the electron-ripplon coupling is sufficiently strong.…”