Low-frequency edge excitations in an electrostatically confined GaAs-AlGaAs two-dimensional electron gas

Abstract
We report an experimental study of the propagation of low-frequency (1-30 MHz) edge excitations in a two-dimensional electron gas confined electrostatically by means of gate induced depletion. This technique allows control of edge channel structure without change of the bulk properties of the electron gas. We have observed a strong dependence of the velocity of the edge excitations on gate voltage and demonstrate that such spectroscopy is a sensitive probe of the two-dimensional edge electronic structure.